GC161 Alcohol And The Brain From Psychiatric To Neuropsychiatric Perspectives
An integrated clinical framework examining alcohol's effects on the brain across both psychiatric manifestations (such as mood disorders, psychosis, and dependence) and neuropsychiatric consequences (including cognitive impairment, Wernicke-Korsakoff syndrome, and alcohol-related brain damage).
This lecture by Dr Heid Lo (HKU Psychiatry) is a bridge lecture connecting psychiatry, neurology, and medicine through the single lens of alcohol. It spans from the addictive/psychiatric dimension (how alcohol hijacks neurotransmission, DSM-5 criteria, withdrawal) through the neuropsychiatric dimension (Wernicke-Korsakoff, cerebellar degeneration, Marchiafava-Bignami, central pontine myelinolysis) to the systemic (hepatic encephalopathy, fetal alcohol syndrome, stroke risk, suicide). The lecture culminates in a must-know clinical pearl: the 6 causes of confusion in alcoholism — a systematic framework for the confused alcoholic patient that examiners love to test.
Why this matters for exams: Alcohol questions appear across psychiatry, neurology, medicine (hepatology), and public health papers. This lecture is the go-to source for psychiatry-neurology crossover material. Past papers repeatedly test definitions of moderate drinking, standard drinks, alcohol and stroke/cardioprotection controversies, and delirium tremens vs alcoholic hallucinosis.
Learning Objectives (from slide 2) [1]
- Understand alcohol-related addictive problems (AUD, intoxication, withdrawal)
- Know alcohol-related medical conditions and brain changes
- Distinguish alcohol-induced psychiatric disorders from comorbid psychiatric conditions
- Understand the bidirectional relationship between alcohol and psychiatric disorders
- List the 6 causes of confusion in alcoholism
1. Alcohol-Related Addictive Problems
Alcohol exerts its CNS effects through two primary mechanisms: [1]
- Increases sensitivity of GABA receptors → enhances inhibitory GABAergic neurotransmission (downregulated in the chronic state)
- Inhibition of NMDA receptors → reduces excitatory glutamatergic neurotransmission (upregulated in the chronic state)
- Indirectly alters release of serotonin, dopamine, norepinephrine, aspartate
Why this matters from first principles:
- Acutely, alcohol is a CNS depressant: it boosts inhibition (GABA) and blocks excitation (glutamate). This explains sedation, impaired coordination, and anxiolysis.
- Chronically, the brain compensates: GABA receptors downregulate (fewer receptors, less responsive), and NMDA receptors upregulate (more receptors, primed for excitation). The brain is now in a "hyper-excitable" state that is masked by ongoing alcohol intake.
- When alcohol is suddenly removed, the mask comes off → withdrawal features are essentially unopposed glutamate excitation + insufficient GABA inhibition → autonomic hyperactivity, seizures, delirium tremens.
- The dopamine alteration explains the rewarding/reinforcing properties that drive addiction.
A problematic pattern of alcohol use leading to clinically significant impairment or distress, manifested by at least 2 of the following within a 12-month period: [1]
| # | Criterion | Conceptual Domain |
|---|---|---|
| 1 | Taken in larger amounts or longer than intended | Loss of control |
| 2 | Persistent desire or unsuccessful efforts to cut down | Loss of control |
| 3 | Great deal of time spent obtaining, using, or recovering | Loss of control |
| 4 | Craving | Compulsive drive |
| 5 | Failure to fulfill major role obligations | Social impairment |
| 6 | Continued use despite interpersonal problems | Social impairment |
| 7 | Important activities given up or reduced | Social impairment |
| 8 | Recurrent use in physically hazardous situations | Risky use |
| 9 | Continued use despite knowledge of physical/psychological harm | Risky use |
| 10 | Tolerance (need more for same effect, or diminished effect at same dose) | Pharmacological |
| 11 | Withdrawal (characteristic syndrome, or substance taken to relieve/avoid withdrawal; benzodiazepine can substitute) | Pharmacological |
Severity grading: 2-3 criteria = Mild; 4-5 = Moderate; ≥6 = Severe
DSM-5 vs ICD-10 Exam Trap
Diagnostic criteria: [1]
- A. Recent ingestion of alcohol
- B. Clinically significant problematic behavioral/psychological changes (inappropriate sexual/aggressive behavior, mood lability, impaired judgment)
- C. One or more: slurred speech, incoordination, unsteady gait, nystagmus, impairment in attention or memory, stupor or coma
- D. Not attributable to another medical condition or substance
Impairment at Different Blood Alcohol Concentrations:
| Blood Alcohol (mg/dL) | Clinical Features |
|---|---|
| 20-30 | Slowed motor performance, decreased thinking ability |
| 30-80 | Increases in motor and cognitive problems |
| 80-200 | Incoordination, judgment errors, mood lability, deterioration in cognition |
| 200-300 | Nystagmus, marked slurring of speech, alcoholic blackouts |
| > 300 | Impaired vital signs and possible death |
Breathalyzer conversion: 0.1 mg/L = blood level 21 mg/dL (×2100) [1]
How to use the table: These are approximate toxicological associations, not deterministic cut-offs. Tolerance, rate of drinking, co-ingestants, age and illness all modify the examination; a seemingly modest concentration does not exclude dangerous impairment, and a high concentration does not prove that alcohol is the only cause of coma. Legal driving thresholds also vary by jurisdiction. The slide's breath-to-blood conversion is an educational approximation, not a substitute for calibrated testing [1].
Key features: [1]
- Transient amnesia lasting hours
- Memory impairment (anterograde) — cannot form new memories of events during the blackout
- No impairment of conscious level — the person appears awake and functioning
- Mechanism: Inhibition of NMDA receptors in hippocampus → failure of long-term potentiation (LTP)
Why this is important: Blackouts are NOT loss of consciousness. The patient is awake, talking, acting — but the hippocampal memory-encoding machinery is offline because NMDA receptors (critical for LTP, the molecular basis of memory consolidation) are blocked by alcohol. This is why people can "do things" during a blackout they have zero recall of the next day. It is a common exam discriminator: blackout ≠ unconsciousness.
Occurs 6-24 hours after last drink [1]
- Autonomic hyperactivity: tremulousness, sweating, nausea, vomiting, anxiety, agitation, tachycardia
- Hypertension, hyperreflexia, insomnia, nightmares, sweating, hyperthermia
- Pathophysiology: Downregulation of GABA receptors + reversal of NMDA inhibition → glutamate overactivity
- Disappears in 2-7 days
The timetable is a pattern, not a clock: symptoms may begin while blood alcohol is still detectable if intake has fallen substantially, and severe disease can occur outside the quoted windows. Previous withdrawal seizures/DT, major comorbidity, pregnancy, older age, electrolyte disturbance or inability to be safely observed lowers the threshold for monitored care [17][18].
Clinical timeline of alcohol withdrawal:
| Time After Last Drink | Feature |
|---|---|
| 6-12 hours | Tremor, anxiety, nausea, sweating, tachycardia |
| 12-24 hours | Alcoholic hallucinosis (auditory, in clear consciousness) |
| 12-48 hours | Withdrawal seizures (generalized tonic-clonic) |
| 24-96 hours | Delirium tremens (peak 48-72h) |
2. Alcohol-Related Medical Conditions and Brain Changes
Severe form of alcohol withdrawal [1]
- Occurs 24-96 hours after abstention
- Confusion, hallucination (typically visual), severe agitation, seizure
- The slide quotes 5% mortality — retain this as a historical teaching figure, not a fixed modern treated-case estimate
- Medical emergency requiring hospitalisation
Current management principles: [17][18]
- Monitored medical care and benzodiazepines are first-line; dosing is titrated to clinical response and local protocol, with airway/respiratory monitoring.
- Do not use carbamazepine as treatment for withdrawal delirium or as generic seizure prophylaxis. Some anticonvulsants have roles in selected mild/moderate withdrawal, but a withdrawal seizure is treated acutely with a quick-acting benzodiazepine; phenytoin is not used for alcohol-withdrawal seizures unless there is another seizure disorder [17][18].
- Give parenteral thiamine promptly when Wernicke encephalopathy is suspected or risk is high, then continue treatment according to local protocol [18].
- Antipsychotics are adjuncts only if severe agitation/hallucinations are not controlled by adequate benzodiazepines; they must not replace benzodiazepines in withdrawal delirium [17].
- Correct fluids, glucose, magnesium, potassium and phosphate as indicated; seek and treat infection, trauma, GI bleeding and other precipitants.
Thiamine and Glucose — Do Not Delay Either Emergency Treatment
Give thiamine as early as possible, preferably before or alongside carbohydrate when feasible, but never delay life-saving glucose for hypoglycaemia. ASAM explicitly states that thiamine and glucose may be given in either order or concurrently. The older “thiamine must always precede glucose” wording on the lecture slide is a useful reminder not to omit thiamine, but it is not a reason to leave a hypoglycaemic patient untreated [17][18].
| Feature | Delirium Tremens | Alcoholic Hallucinosis |
|---|---|---|
| Consciousness | Clouded sensorium | Clear consciousness |
| Hallucinations | Typically visual | Typically auditory |
| Onset | 24-96h after cessation | During heavy drinking or shortly after |
| Trigger | Reduction/cessation of alcohol | Chronic heavy drinking |
| Other features | Confusion, agitation, seizures, autonomic instability | Distressing auditory content, may develop into schizophrenia-like picture |
| Treatment | Benzodiazepines + monitored supportive care | Urgent medical/withdrawal assessment; abstinence treatment; specialist-guided antipsychotic if needed |
"Differentiate from delirium tremens — reduction in alcohol intake, clouded sensorium, visual hallucination" — this is a direct slide note from the lecture and is frequently tested [1].
Clinical features: [1]
- Confusion
- Memory impairment / Attention problems / Hallucination
- Ophthalmoplegia / Nystagmus
- Ataxia (truncal)
- Peripheral neuropathy (50%)
- Hypothermia
- Apathy
- Coma (rare)
Key facts: [1]
- Mostly alcoholic, some non-alcoholic
- Caused by thiamine deficiency
- Only 20% detected in life (Harper 1983) — historical autopsy-era estimate illustrating underdiagnosis
- Medical emergency
- 20% mortality — historical cohort figure, not a contemporary individual prognosis
- Treatment: IM/IV Thiamine
- Progression to Korsakoff's psychosis in 84% (Victor 1989) — historical series, not a modern bedside probability
The classic triad is confusion + ocular abnormality + ataxia, but waiting for all three misses disease. In a malnourished patient or one with harmful alcohol use, any compatible change should lower the threshold for immediate parenteral thiamine; treatment should not wait for imaging or a thiamine level [18].
Why thiamine deficiency causes Wernicke: Thiamine (vitamin B1) is a cofactor for pyruvate dehydrogenase, α-ketoglutarate dehydrogenase, and transketolase. These enzymes are critical for cellular energy metabolism. Brain regions with high metabolic demands (periventricular grey matter, mammillary bodies, medial thalamus, periaqueductal grey) are preferentially vulnerable [1][3].
Key features: [1]
- Severe, often persistent anterograde memory impairment
- Inability to learn and later recall new information
- Confabulation ± (patient fills memory gaps with fabricated stories, not deliberately lying)
- No clouding of consciousness
- Other cognition may be relatively preserved, but executive and broader cognitive deficits can coexist
Why early treatment matters: Korsakoff syndrome reflects structural injury within the diencephalic memory network, so deficits are often long-lasting. “Irreversible” and “no cure” are too absolute: recovery varies and may continue with abstinence, nutrition, thiamine repletion and cognitive rehabilitation. The lecture's 84% figure came from a historical series; it should reinforce urgency, not be quoted as a current individual risk [1][18].
Pathological findings: [1]
- Petechial haemorrhages, neuronal loss, gliosis, brown discolouration
- Locations: periventricular grey matter, 3rd ventricle, Sylvian aqueduct, 4th ventricle, diencephalon, midbrain, pons, medulla
Non-alcoholic causes of WKS: [1]
| Cause | Mechanism of Thiamine Deficiency |
|---|---|
| Hyperemesis of pregnancy | Prolonged vomiting → ↓intake |
| Systemic malignancy | Catabolic state → ↑demand, ↓intake |
| GI surgery | Malabsorption |
| Haemodialysis / peritoneal dialysis | Thiamine loss |
| Prolonged intravenous feeding | Glucose load without thiamine |
| Refeeding after prolonged fasting/starvation | Glucose load depletes remaining thiamine |
| Anorexia nervosa | ↓intake |
| Dieting/starvation | ↓intake |
| Gastric plication | Malabsorption |
| AIDS | Multiple factors |
Common defect: Thiamine deficiency [1]
Thiamine-deficiency amnesic syndromes → affect diencephalon and brainstem [1] Non-thiamine-deficiency amnesic syndromes → affect medial temporal lobe [1]
Other causes of medial temporal lobe amnesic syndrome: [1]
- Closed head trauma, penetrating wounds, focal tumour, encephalitis (especially HSV), hypoxia (CO poisoning), infarction (posterior cerebral artery territory), neurosurgery
This distinction matters because the clinical flavour differs: diencephalic lesions produce more confabulation and disorientation, while temporal lobe lesions produce more "pure" amnesia [3].
Brain Memory Circuit (from slide 22): [1]
Thiamine-deficiency amnesia (Korsakoff) preferentially damages the medial diencephalon circuit; many non-thiamine causes (trauma, HSV encephalitis, PCA infarction) damage the medial temporal lobe circuit. On the slide diagram, the two systems are not isolated boxes: both communicate with frontal and sensory-association cortex. That shared cortical interface explains how injury at either relay can disrupt encoding and retrieval, while diencephalic disease may additionally impair executive control and produce confabulation [1].
West Haven Criteria — 4 stages of severity: [1]
| Stage | Features |
|---|---|
| Stage 1 | Trivial lack of awareness, shortened attention span, impaired addition/subtraction, hypersomnia/insomnia/sleep inversion, euphoria or depression. Asterixis can be detected |
| Stage 2 | Lethargy or apathy, mild disorientation, inappropriate behavior, slurred speech, obvious asterixis |
| Stage 3 | Gross disorientation, bizarre behavior, semi-stupor to stupor, asterixis generally absent |
| Stage 4 | Coma |
Glasgow Coma Scale may also be used [1]
Pathophysiology (from supporting sources): Ammonia (NH3) accumulates due to impaired hepatic detoxification and portosystemic shunting → crosses BBB → metabolised to glutamine in astrocytes → ↑intracellular osmolarity → astrocyte swelling → cerebral edema and neuroinflammation [4][5].
Hepatic Encephalopathy Is a Clinical Diagnosis
An elevated ammonia concentration alone neither diagnoses nor grades hepatic encephalopathy and serial values should not drive treatment. If an ammonia result is normal in a patient thought to have overt HE, reconsider the diagnosis. Always search for precipitants and mimics, including GI bleeding, infection, constipation, sedatives, electrolyte disturbance, renal dysfunction, withdrawal, hypoglycaemia, trauma and Wernicke encephalopathy [22].
Slide teaching (historical epidemiological figures should not be used for individual risk prediction): [1]
- The slide quotes a 30% chance with heavy drinking and a US prevalence of 1-4 per 1000 live births
- Brain findings: Microcephaly, agenesis of corpus callosum, cerebellar hypoplasia
- A preventable cause of intellectual disability and neurodevelopmental impairment
- Low birth weight
- Growth retardation
Read the facial photograph (slide 25): Prioritise the three sentinel facial features: short palpebral fissures, a smooth philtrum and a thin upper-lip vermilion. The photograph also labels flat midface/low nasal bridge, epicanthal folds, short nose and micrognathia, but these are less specific and must not be used alone to diagnose FAS. Fetal alcohol spectrum disorders (FASDs) are a group of lifelong conditions; diagnosis integrates prenatal alcohol exposure where ascertainable, growth, neurodevelopment/CNS findings and characteristic facial features rather than a single photograph [19].
Prevention: There is no known safe amount, safe time or safe type of alcohol in pregnancy. Do not use the slide's “30%” figure to reassure an individual pregnancy; advise abstinence and arrange appropriate antenatal/teratology assessment after exposure without stigma [19].
Key features: [1]
- Thiamine deficiency
- Atrophy of cerebellum (vermis)
- Unsteady gait, truncal instability, lower limb ataxia
- Postural hand tremor, dysarthria, nystagmus
- Degeneration of Purkinje cells
Why the vermis? The cerebellar vermis controls truncal coordination and gait. The Purkinje cells are particularly metabolically active and vulnerable to thiamine deficiency and direct alcohol toxicity. This is why alcoholic cerebellar degeneration predominantly affects gait and truncal stability rather than fine limb coordination.
Imaging findings (slides 27-28): Sagittal T1-weighted MRI shows atrophy of the cerebellar vermis with prominent intervening spaces between folia. Gross pathology comparison between non-alcoholic and alcoholic specimens demonstrates atrophy of the cerebellar folia and widening of the sulci, particularly involving the anterior superior aspect of the cerebellar vermis [1].
Key features: [1]
- Classically associated with chronic harmful alcohol use and malnutrition; originally described in Italian drinkers of crude red wine
- Subacute demyelination disease
- Fits, spasticity, rigidity, paralysis
- Coma, death
- Affects mid corpus callosum (vacuolation and degeneration)
- 40-60 years old
- Frontal lobe syndrome, dementia, personality change
Why the corpus callosum? The exact mechanism is unclear but thought to involve direct toxic effects of alcohol metabolites and nutritional deficiency targeting the myelin of the largest white matter tract. The corpus callosum connects the two hemispheres, so demyelination here produces disconnection syndromes and frontal lobe dysfunction.
Read the MRI (slide 30): First identify the corpus callosum as the midline C-shaped commissural tract on the sagittal image, then confirm the matching midline callosal lesion on the axial image. The central callosal fibres may be preferentially involved (the described “sandwich” pattern), but imaging and clinical context are needed because callosal signal is not specific. The historical crude-red-wine association is not a diagnostic requirement [1].
Key features: [1]
- Demyelination of pons
- Dysarthria / dysphagia
- Spastic paralysis of all 4 limbs (quadriparesis)
- Most classically follows an excessive rise in sodium during correction of chronic hyponatraemia — hypertonic saline itself is not intrinsically the cause
- Personality change, inappropriate affect, delusion
- Risk contexts include alcohol use disorder, malnutrition, hypokalaemia, cirrhosis/liver transplant, uraemia/dialysis and prolonged vomiting
Read the images (slides 32-33): On the axial T2 MRI, the central pontine high signal is relatively symmetric, with peripheral fibres comparatively spared; extrapontine sites may also be involved, hence the broader term osmotic demyelination syndrome (ODS). On the myelin-stained histology, normally blue myelin is absent in the central basis pontis, matching the MRI distribution [1].
Central Pontine Myelinolysis — The Rate of Sodium Correction
The critical teaching point is to avoid overcorrection of chronic hyponatraemia, especially in patients with harmful alcohol use, malnutrition, severe hypokalaemia or advanced liver disease. The European guideline limits the rise to 10 mmol/L in the first 24 hours and 8 mmol/L in each subsequent 24 hours; many protocols use a stricter ≤8 mmol/L in any 24 hours for patients at high risk. These are ceilings, not targets, and no rate guarantees safety: monitor sodium and urine output closely and involve experienced clinicians if the trajectory overshoots [20].
Summary from lecture: [1]
| Stroke Type | % of Strokes | Light/Moderate Drinking | Heavy Drinking |
|---|---|---|---|
| Haemorrhagic | 15% | — | ↑Risk |
| Ischaemic | 85% | ↓Risk | ? |
Wine specifically: Copenhagen City Heart Study showed wine intake ↓ risk of stroke (after adjusting for confounders), while beer/spirits showed no relation [1] Both findings are marked as CONTROVERSIAL on the slides [1]
This table summarises older observational evidence, not a prescribing recommendation. Apparent protection is vulnerable to residual confounding and “sick-quitter”/former-drinker bias. Current AHA guidance says not to start wine or any alcohol for cardiovascular benefit; heavy and binge drinking are consistently associated with worse cardiovascular outcomes, including stroke [21]. WHO also states that no pattern of alcohol use is risk-free [23].
From the lecture: [1]
- Impairment in visuospatial processing
- Memory impairment
- EEG abnormalities
- Reduction in cerebral blood flow
- Reduction in cerebral glucose metabolism
Historical statistics quoted on slide 37: [1]
- 7% of alcohol abusers die of suicide
- Alcoholism is a factor in 30% of all completed suicides
- 50% of suicide attempts have consumed alcohol at the time of the attempt
- 96% of alcoholics who die by suicide continue alcohol use up to the end of their lives
Do not memorise these old, source- and population-dependent percentages as current epidemiology. The durable clinical point is that both acute intoxication and alcohol use disorder heighten suicide risk through disinhibition, impulsivity, comorbid depression/psychosis and social harms. Ask directly about thoughts, intent, plans, means and past attempts; do not defer assessment merely because the patient is intoxicated, and reassess as sobriety returns.
3. Alcohol-Related Psychiatric Disorders
The lecture makes a critical distinction between alcohol-induced psychiatric disorders (caused by alcohol, resolve with abstinence) and alcohol-comorbid psychiatric disorders (independent psychiatric illness co-existing with alcoholism).
3.1 Alcohol-Induced Psychiatric Disorders
Key features: [1]
- Chronic heavy drinkers
- Auditory hallucination in clear consciousness
- Distressing in content
- Some develop schizophrenia, some remit after stopping alcohol
- Treatment begins with medical/withdrawal assessment and support for abstinence; an antipsychotic may be needed under specialist guidance
Key features: [1]
- Chronic heavy drinking
- Clear sensorium
- Schizophrenia-like syndrome
- Remission on stopping alcohol
- Recurrence with relapse of alcoholism
Key features: [1]
- Moderate or heavy alcohol use
- Major depression or mania
- Usually improves with sustained abstinence; the slide uses a four-week teaching window
Key features: [1]
- Symptoms occur while patient on heavy alcohol consumption
- Symptoms may subside gradually with abstinence; the slide notes persistence for up to six months
- Can manifest as: GAD, panic disorder, phobic anxiety disorders, social phobia, OCD, PTSD
- Must be distinguished from alcohol withdrawal syndrome
Alcohol-Induced vs Withdrawal Anxiety
This is an exam trap, but time alone is not diagnostic. Withdrawal anxiety generally follows a marked reduction in intake and is accompanied by tremor/autonomic hyperactivity; an alcohol-induced anxiety syndrome has a close temporal relation to intoxication or withdrawal and should improve as the substance effect resolves. Persistent symptoms require reassessment for an independent anxiety disorder, PTSD, medication/drug effects and medical mimics. Treat severe depression, psychosis or suicidality immediately rather than waiting for an arbitrary alcohol-free interval [1].
How to identify comorbid (independent) psychiatric disorders: [1]
- Evidence of psychiatric disorders before onset of alcohol abuse/dependence
- Evidence of persistent psychiatric symptoms during sustained alcohol-free periods
- First-degree biological relative with documented psychiatric disorder
Prevalence of alcoholism in various psychiatric conditions: [1]
| Psychiatric Condition | % with Comorbid Alcoholism |
|---|---|
| Antisocial personality disorder | 80% |
| Bipolar I disorder | 60% |
| Schizophrenia | 30% |
| Drug addiction | 20% |
| Anxiety disorders (social phobia, panic disorder) | Common |
The percentages in this slide table are historical teaching estimates and should not be transferred to a different population as prevalence facts. The more durable lesson is dual diagnosis is common: screen in both directions and treat AUD and the psychiatric disorder together.
Why schizophrenia patients drink (from the lecture): [1]
- Alcohol decreases feeling of isolation
- Temporarily reduces symptoms of anxiety/depression/insomnia
- But INCREASES psychotic symptoms & mood swings
- Leads to disruptive behaviour, suicide, treatment non-compliance, drug abuse, poor clinical outcome
- Drug accumulation due to hepatic damage (impaired metabolism of antipsychotics)
Cross-addiction: [1]
- 20% of drug abusers are alcoholic
- Alcoholics are 6 times more prone to become drug abusers
These are also historical slide figures. Clinically, ask about sedatives, opioids, stimulants, cannabis and prescribed medicines rather than inferring a specific probability.
The lecture emphasizes a bidirectional, confounded relationship: [1] Alcoholism ↔ Psychiatric symptoms, with confounding factors complicating causal inference
This means: alcohol can cause or amplify psychiatric symptoms; psychiatric symptoms may drive drinking; and shared factors (genetic vulnerability, trauma, social adversity, other substances and medication effects) can produce both. The slide's two-way arrow is therefore a reminder to establish a timeline, seek collateral information and avoid assuming causation from coexistence alone [1].
MUST KNOW — 6 Causes of Confusion in Alcoholism
This is the single most exam-relevant list from this lecture. When faced with a confused alcoholic patient, systematically consider all six: [1]
- Intoxication — recent heavy drinking, ↑BAC, resolves with time
- Delirium Tremens — 24-96h after cessation, clouded consciousness, visual hallucinations, autonomic storm, seizures
- Head Injury — alcoholics are prone to falls and assaults; always consider subdural haematoma (especially chronic SDH in elderly alcoholics)
- Metabolic Disturbances — hypoglycaemia (alcohol inhibits gluconeogenesis via NAD+ consumption by alcohol dehydrogenase), hyponatraemia, hypomagnesaemia, hypokalaemia, hypophosphataemia
- Hepatic Encephalopathy — look for cirrhosis and precipitants such as GI bleeding, infection, constipation, renal/electrolyte disturbance and sedatives; ammonia does not diagnose or grade it
- Wernicke Encephalopathy — thiamine deficiency, ophthalmoplegia, ataxia, confusion; medical emergency
Why this list matters clinically: A patient with harmful alcohol use may have several simultaneously—for example DT + hypoglycaemia + subdural haematoma. Use the six as a mnemonic, not a closed differential: also assess ABCs, sepsis/meningitis, stroke, seizures/postictal state, carbon monoxide, medication effects and other toxidromes. Check bedside glucose immediately, give prompt thiamine when indicated, and obtain neuroimaging when trauma or a focal deficit is possible.
5. Integration with Other GC Material
Alcohol causes multiorgan involvement with multiple simultaneous presentations: psychiatric/CNS/seizures/cardiomyopathy/AF/gout/acute and chronic pancreatitis [7] Concomitant presentations in alcoholic liver disease include: withdrawal (D2+ onward), delirium tremens, infections, cirrhotic complications (variceal bleeding, ascites, SBP, HE) [7]
- US/AHA standard drink = 14 grams of pure alcohol (this is the convention tested in these past papers; “standard drink” size varies by country) [9][21]
- AHA upper limit for people who choose to drink: up to 1 drink/day for women and up to 2 drinks/day for men. This is not a safe threshold or recommendation to start drinking [21][23].
- Equivalents: 1 standard drink ≈ 12 oz (355 mL) beer (5%), 5 oz (148 mL) wine (12%), 1.5 oz (44 mL) spirits (40%)
The 2025 MCQ asks about current HK tax duty on wine — the answer is 0% (Hong Kong abolished wine duty in 2008 for wine/alcohol ≤30% ABV) [10].
6. Exam Intelligence
| Trap | Correct Understanding |
|---|---|
| Alcoholic blackout = loss of consciousness | No. Blackout = transient amnesia in clear consciousness; NMDA inhibition in hippocampus blocks LTP |
| DT = any alcohol withdrawal | No. DT is severe withdrawal with delirium and autonomic hyperactivity; the slide's 24-96 h and 5% figures are historical teaching ranges, not rigid rules |
| Alcoholic hallucinosis = DT | No. Hallucinosis = auditory hallucinations in clear consciousness during/after heavy drinking. DT = visual hallucinations in clouded consciousness during withdrawal |
| Korsakoff = general dementia | No. Korsakoff is a severe amnestic syndrome with clear consciousness; executive and other cognitive deficits can coexist |
| Wernicke always presents with classic triad | No. Do not wait for the full triad; give parenteral thiamine promptly when clinical suspicion is present |
| CPM caused by hyponatraemia | No. ODS most classically follows an excessive sodium rise during correction of chronic hyponatraemia; alcohol use and malnutrition increase risk |
| Alcohol-induced mood disorder obeys a fixed four-week rule | No. Establish temporality and reassess during abstinence, but treat urgent mood symptoms and suicide risk immediately |
| Moderate alcohol is cardioprotective | Not established. Confounding can create apparent benefit; AHA says non-drinkers should not start for cardioprotection |
- Define a standard drink and moderate consumption (appears in 2017, 2020, 2021, 2022 papers)
- 6 causes of confusion in alcoholism
- DT vs alcoholic hallucinosis
- Wernicke-Korsakoff pathology and treatment
- Alcohol-induced vs comorbid psychiatric disorders — distinguishing features
- DSM-5 criteria for AUD
- Mechanism of alcohol (GABA/NMDA) and how this explains withdrawal
- Fetal alcohol syndrome features
| Domain | Approach in Alcoholic Patient |
|---|---|
| History | CAGE/AUDIT screening; quantity/frequency/duration; last drink timing; previous withdrawal/seizures/DT; psychiatric history; social/occupational impact; drug co-use; family history |
| Examination | Stigmata of CLD; nutritional status; neurological exam (cerebellar signs, nystagmus, ophthalmoplegia, peripheral neuropathy); mental state exam; tremor; GCS |
| Investigations | Bedside glucose first; then targeted FBC, renal/liver profile, Na/K/Mg/PO4, coagulation and toxicology/alcohol level as the presentation requires. GGT and macrocytosis are nonspecific and cannot diagnose AUD. Do not wait for a thiamine level before treatment. Ammonia alone neither diagnoses nor grades HE. CT brain for trauma/focal signs or unexplained reduced consciousness; MRI may support Wernicke/ODS but a normal scan does not exclude Wernicke |
| Acute management | ABCs and bedside glucose; give parenteral thiamine promptly when indicated without delaying dextrose; benzodiazepines are first-line for withdrawal; correct electrolytes and treat infection/bleeding/other precipitants. Use a validated withdrawal scale only in a patient who can communicate reliably—CIWA-Ar is not appropriate for delirious or non-communicative patients [17] |
| Long-term Management | Motivational interviewing; relapse prevention (naltrexone, acamprosate, disulfiram); treat comorbid psychiatric disorders; AA/support groups; nutritional rehabilitation; hepatology follow-up; social worker involvement |
| Prevention | Public health alcohol policy (taxation, advertising regulation); screening in primary care (AUDIT); brief interventions; patient education; no alcohol in pregnancy; do not recommend starting alcohol for cardioprotection |
High Yield Summary
Must-know points
- Mechanism: acute alcohol enhances GABAergic inhibition and inhibits NMDA/glutamate signalling; chronic adaptation explains hyperexcitable withdrawal.
- AUD (DSM-5): ≥2 of 11 criteria in 12 months; severity by count.
- Blackout: anterograde amnesia while awake, not loss of consciousness.
- DT: withdrawal delirium with impaired attention/awareness and autonomic hyperactivity; benzodiazepines are first-line, antipsychotics adjunctive only.
- Wernicke: do not wait for the full triad or imaging; give prompt parenteral thiamine and do not delay emergency glucose.
- Korsakoff: persistent amnestic syndrome with possible confabulation and executive deficits; recovery is variable, not impossible.
- Visual discriminators: anterior-superior vermian atrophy (alcohol-related cerebellar degeneration); callosal lesion (Marchiafava-Bignami); symmetric central pontine T2 signal (ODS); smooth philtrum + thin upper lip + short palpebral fissures (FAS).
- Six-slide mnemonic for confusion: intoxication, DT, head injury, metabolic disturbance, HE and Wernicke—plus an open differential for infection, stroke, seizures and other toxins.
- Alcohol-induced vs independent disorder: establish the longitudinal timeline; no single four-week or six-month cut-off replaces reassessment and urgent risk treatment.
- Public health: a US/AHA standard drink contains 14 g alcohol; AHA limits for those choosing to drink are ≤1/day for women and ≤2/day for men, but non-drinkers should not start for cardioprotection.
- Pregnancy: no known safe amount, time or type of alcohol.
- Historical numbers: the lecture's Wernicke/DT/suicide/comorbidity percentages are contextual evidence, not current bedside probabilities.
Active Recall - Lecture Notes
[1] Lecture slides: GC 161. Alcohol and the Brain From Psychiatric to Neuropsychiatric Perspectives.pdf (all slides p1-50) [2] Lecture slides: CFB (PSY02) Classification and Diagnosis of Psychiatric Illness.pdf [3] Senior notes: Ryan Ho Psychiatry.pdf (Section 5.1.2 Alcohol-related Disorders, p97-107) [4] Senior notes: MBBS Final MB (Medicine) (Felix PY Lai).pdf (Hepatic Encephalopathy, p807) [5] Senior notes: MBBS Final MB (Surgery) (Felix PY Lai).pdf (Hepatic Encephalopathy, p463) [6] Senior notes: Ryan Ho Neurology.pdf (Coma, p92) [7] Lecture slides: GC 240. MASLD and Alcoholic Liver Disease.pdf (p14-15) [8] Lecture slides: GC 037. Common neurological problems in older people.pdf (p23) [9] Past papers: 2017 Fourth Summative SAQ.pdf (Q11, p5) [10] Past papers: 2025 Fourth Summative MCQ.pdf (Q26, p11) [17] American Society of Addiction Medicine. The ASAM Clinical Practice Guideline on Alcohol Withdrawal Management. 2020. https://downloads.asam.org/sitefinity-production-blobs/docs/default-source/guidelines/awg-3-20-20.pdf [18] NICE. Alcohol-use disorders: diagnosis and management of physical complications (CG100). Updated 2017. https://www.nice.org.uk/guidance/cg100/chapter/recommendations [19] US Centers for Disease Control and Prevention. About Fetal Alcohol Spectrum Disorders (FASDs). Updated 2025. https://www.cdc.gov/fasd/about/index.html [20] Spasovski G, et al. Clinical practice guideline on diagnosis and treatment of hyponatraemia. European Journal of Endocrinology. 2014;170:G1-G47. https://academic.oup.com/ejendo/article/170/3/G1/6668028 [21] American Heart Association. Alcohol Use and Cardiovascular Disease: Top Things to Know. 2025. https://professional.heart.org/en/science-news/alcohol-use-and-cardiovascular-disease/top-things-to-know [22] AASLD. Why shouldn't ammonia be used in the diagnosis and management of hepatic encephalopathy? 2023. https://www.aasld.org/liver-fellow-network/core-series/why-series/why-shouldnt-ammonia-be-used-diagnosis-and-management [23] World Health Organization. Alcohol: fact sheet. 2024. https://www.who.int/news-room/fact-sheets/detail/alcohol
GC160 The Woman Needs That Drug Oral Contraceptives Drugs Affecting Uterine Motility
Oral contraceptives are estrogen-progestin or progestin-only formulations that prevent ovulation, alter the endometrium, and thicken cervical mucus, while uterine motility drugs such as oxytocin, ergot alkaloids, prostaglandins, and tocolytics either stimulate or inhibit uterine contractions to manage labor, postpartum hemorrhage, or preterm labor.
GC163 I Am A Superman Bipolar Disorder
Bipolar disorder is a chronic mood disorder characterized by episodic fluctuations between mania (or hypomania)—during which grandiose delusions such as believing oneself to be a superhero may occur—and depression, with intervening periods of euthymia.