I now have all the textbook evidence needed. Let me compile the full, well-referenced answers.
General Medicine Paper I - MCQ Answers
(a) Grade of Hepatic Encephalopathy → (iii) III
Answer: Grade III
The West Haven Criteria grades hepatic encephalopathy as follows:
| Grade | Features |
|---|
| I | Mild confusion, euphoria/anxiety, decreased attention, slowed thinking |
| II | Lethargy, moderate confusion, obvious personality change, disorientation to time |
| III | Somnolent but arousable, gross disorientation, asterixis present, triphasic waves on EEG |
| IV | Coma (unresponsive to painful stimuli) |
The clinical picture given - drowsy but arousable to verbal commands, asterixis, and EEG triphasic waves - is the textbook description of Grade III. As Goldman-Cecil Medicine confirms, the EEG "typically shows generalized slow waves and triphasic waves" in overt hepatic encephalopathy, and Grade III specifically features somnolence with preserved arousability.
- Harrison's Principles of Internal Medicine 22E; Goldman-Cecil Medicine
(b) Cause NOT of primary headache → (iv) Systemic infection
Answer: Systemic infection
Primary headaches are those in which head pain itself is the disorder, with no identifiable underlying cause. Per the International Classification of Headache Disorders 3rd edition (ICHD-3), primary headaches include:
- Migraine
- Tension-type headache
- Cluster headache (trigeminal autonomic cephalalgias)
Systemic infection (e.g., fever, sepsis, meningitis) causes a secondary headache - one that is attributed to an identifiable underlying condition. Secondary headaches include those due to infection, trauma, vascular disorders, intracranial pressure changes, and more.
- Harrison's Principles of Internal Medicine 22E; Bradley and Daroff's Neurology in Clinical Practice
(c) Chest pain feature with highest likelihood of AMI → (ii) Radiation to both arms or shoulders
Answer: Radiation to both arms or shoulders
Harrison's explicitly states: "Radiation to both arms has a particularly high association with MI as the etiology." This bilateral arm radiation carries a higher positive likelihood ratio for acute MI than radiation to either arm alone.
Regarding the other options:
-
Radiation to right arm alone has a moderate positive LR (~2.2)
-
Radiation to left arm is common but less specific
-
Diaphoresis is also a predictor of AMI (option iv), but among the choices, bilateral arm radiation has the highest documented likelihood ratio
-
Harrison's Principles of Internal Medicine 22E, History section on chest pain
(d) Parameter that does NOT warrant further evaluation → (iii) Abdominal pain
Answer: Abdominal pain
In a patient with diarrhea, the following are "alarm features" that warrant further evaluation:
- Grossly bloody stool - suggests invasive pathogen or inflammatory bowel disease
- Fever ≥38.5°C (101°F) - suggests invasive infection
- Immunocompromised state - predisposes to severe, atypical, or opportunistic infections
Abdominal pain by itself is a common, expected accompaniment of diarrheal illness and does not independently trigger further evaluation the way the other alarm features do. Crampy abdominal pain is intrinsic to most forms of acute diarrhea (infectious, motility-related, etc.) and is not a "red flag" differentiating feature on its own.
(e) Feature NOT of Wernicke's encephalopathy → (i) Vertical nystagmus
Answer: Vertical nystagmus
Wernicke's encephalopathy (thiamine deficiency) classically presents with the triad:
- Ophthalmoplegia (lateral rectus palsy/gaze palsy)
- Cerebellar ataxia (mainly gait)
- Mental impairment (global confusion)
The nystagmus in Wernicke's encephalopathy is characteristically horizontal nystagmus, not vertical. Harrison's states: "Wernicke's encephalopathy consists of horizontal nystagmus, ophthalmoplegia, cerebellar ataxia, and mental impairment." Adams and Victor's Neurology also emphasizes horizontal nystagmus as the typical finding, noting it responds rapidly to thiamine.
Vertical nystagmus can rarely occur as a minor component (one case series notes it can appear with vestibular components), but it is NOT the classic or defining feature. The question is asking what is "not a feature," and the standard teaching in every major textbook lists horizontal nystagmus as the hallmark - making vertical nystagmus the odd one out.
- Harrison's Principles of Internal Medicine 22E; Adams and Victor's Principles of Neurology 12E; Kaplan and Sadock's Synopsis of Psychiatry
Summary Table
| Q | Answer | Key Point |
|---|
| (a) | (iii) Grade III | Drowsy but arousable + asterixis + EEG triphasic waves = Grade III HE |
| (b) | (iv) Systemic infection | Secondary headache, not primary |
| (c) | (ii) Both arms | Bilateral arm radiation = highest LR for AMI |
| (d) | (iii) Abdominal pain | Expected in diarrhea; not an alarm feature |
| (e) | (i) Vertical nystagmus | Wernicke's = horizontal nystagmus classically |
