1) A large lesion in dominant parietal lobe can cause, a) Contralateral hemiparesis b) right left distortion. c) receptive aphasia d) contralateral inferior quadranopia e) disorganized behavior
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I now have comprehensive textbook data. Here is the full analysis:
Dominant Parietal Lobe Lesion - Answer Analysis
The dominant parietal lobe in most people is the left parietal lobe. A large lesion here produces a characteristic set of deficits. Let's evaluate each option:
✅ a) Contralateral hemiparesis — TRUE
A large parietal lobe lesion causes mild hemiparesis or poverty of movement on the contralateral side. This is because a large lesion extends to involve adjacent motor fibers or the posterior part of the internal capsule. Adams and Victor's lists "mild hemiparesis or poverty of movement (variable)" as a feature of unilateral parietal lobe disease (both dominant and non-dominant).
✅ b) Right-left disorientation — TRUE
This is a classic feature of the dominant (left) parietal lobe. It forms part of Gerstmann's syndrome, which consists of:
- Right-left disorientation
- Finger agnosia
- Agraphia (dysgraphia)
- Acalculia (dyscalculia)
Gerstmann's syndrome is caused by a lesion in the inferior parietal lobule (angular gyrus) of the dominant hemisphere. - Adams and Victor's Principles of Neurology, 12th Ed.
❌ c) Receptive aphasia — FALSE (not a typical feature)
Receptive (Wernicke's) aphasia localizes to the posterior superior temporal gyrus (Brodmann area 22), which is in the temporal lobe, not the parietal lobe. Dominant parietal lobe lesions can cause conduction aphasia (supramarginal gyrus), alexia, or anomia, but NOT classic receptive (Wernicke's) aphasia. This option is incorrect. - Localization in Clinical Neurology, 8e
✅ d) Contralateral inferior quadrantanopia — TRUE
The optic radiations pass through the parietal lobe (the superior fibers/parietal radiations carry information from the inferior visual field). A parietal lobe lesion interrupts these superior optic radiation fibers, producing a contralateral inferior quadrantanopia (or homonymous hemianopia with parietal lobe-type characteristics). - Kanski's Clinical Ophthalmology, 10th Ed.
Mnemonic: Parietal lobe lesion → "PITS" = Parietal = Inferior visual field defect (like a pie falling down from the sky).
❌ e) Disorganized behavior — FALSE (not a dominant parietal feature)
Disorganized/confused behavior is listed under non-dominant parietal lobe lesions (right side), specifically "Confusion." The dominant parietal lobe is associated with language, praxis, and calculation - not behavior or confusion. Behavioral/psychiatric features and anosognosia are predominantly non-dominant parietal phenomena. - Adams and Victor's Principles of Neurology, 12th Ed.
Summary Table
| Option | Feature | Lobe Affected | Correct? |
|---|---|---|---|
| a | Contralateral hemiparesis | Either parietal lobe (large lesion) | ✅ TRUE |
| b | Right-left disorientation | Dominant parietal (Gerstmann's) | ✅ TRUE |
| c | Receptive aphasia | Temporal lobe (Wernicke's area) | ❌ FALSE |
| d | Contralateral inferior quadrantanopia | Parietal optic radiation | ✅ TRUE |
| e | Disorganized behavior | Non-dominant parietal | ❌ FALSE |
Correct Answers: a, b, d
The classic dominant parietal lobe syndrome involves:
- Gerstmann's syndrome (right-left disorientation, finger agnosia, agraphia, acalculia)
- Conduction aphasia (not receptive)
- Contralateral inferior quadrantanopia (parietal optic radiation involvement)
- Mild contralateral hemiparesis with large lesions
- Bilateral ideomotor apraxia
29) A 50-year-old man presented with sudden onset aphasia and mouth deviation to left side.There was motor paralysis and loss of the sensation on the right side of the body that developed within 2 hours. On admission the BP was 170/110 mmHg and PR – 88 bpm. What is the most appropriate management option? a) Oral warfarin b) IV labetalol infusion c) IV tissue plasminogen activator d) Infusion of heparin 5mg/ day e) S/C enoxaparin
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Excellent - I now have all the key information needed for a complete answer.
Answer: c) IV tissue plasminogen activator (tPA)
Clinical Analysis
Diagnosis: Acute Ischemic Stroke - Left MCA Territory
This patient's presentation clearly points to an acute ischemic stroke in the left (dominant) middle cerebral artery (MCA) territory:
| Feature | Localization |
|---|---|
| Sudden onset aphasia | Left hemisphere (dominant) |
| Mouth deviation to left | Contralateral facial paresis - left UMN lesion |
| Right-sided motor paralysis | Left hemisphere lesion |
| Right-sided sensory loss | Left hemisphere lesion |
| Onset within 2 hours | Acute ischemic stroke - within thrombolytic window |
Why IV tPA is the Correct Answer
IV recombinant tPA (alteplase) is the only FDA-approved thrombolytic for acute ischemic stroke and must be given within a 3 to 4.5-hour window from symptom onset (or last known well time).
This patient presented within 2 hours - squarely within the treatment window. - Frameworks for Internal Medicine; Miller's Anesthesia, 10e
Key BP note: For tPA eligibility, blood pressure must be brought below 185/110 mmHg before administration. This patient's BP is 170/110 mmHg - the diastolic is at the threshold. If it remains at 110, it would need to be treated first (e.g., with labetalol), but the definitive therapy is still tPA, not labetalol alone. - Frameworks for Internal Medicine
Why the Other Options are Wrong
❌ a) Oral warfarin
Warfarin takes days to reach therapeutic anticoagulation and has no role in acute stroke management. It is used for secondary prevention in cardioembolic strokes (e.g., atrial fibrillation), never in the acute phase.
❌ b) IV labetalol infusion
Aggressive blood pressure lowering in acute ischemic stroke is harmful - it reduces perfusion to the ischemic penumbra. AHA guidelines recommend not lowering BP unless it is above 220/130 mmHg (in non-tPA candidates) or above 185/110 mmHg (if tPA is being given). At 170/110 mmHg, labetalol infusion alone is not indicated and is certainly not the primary management. - Bradley and Daroff's Neurology in Clinical Practice
❌ d) IV heparin infusion
Heparin has not been shown to improve outcomes in acute ischemic stroke and carries a significant risk of hemorrhagic transformation. It is not recommended for acute stroke treatment. The dose given in the option ("5 mg/day") is also clinically nonsensical for heparin (heparin is dosed in units, not mg, and therapeutic doses are far higher).
❌ e) S/C enoxaparin
Low-molecular-weight heparin (enoxaparin) is used for DVT prophylaxis in immobilized stroke patients, not for acute stroke treatment. It does not dissolve the clot causing the ischemic event.
Key Thrombolysis Points to Remember
- Window: 0-4.5 hours from symptom onset (0-3 hours for all eligible patients; 3-4.5 hours with additional exclusion criteria)
- BP requirement: Must be <185/110 mmHg before and <180/105 mmHg during/after tPA
- Dose: Alteplase 0.9 mg/kg IV (max 90 mg); 10% as bolus, 90% over 60 minutes
- Do NOT give aspirin within 24 hours of tPA administration
- Exclude hemorrhagic stroke with CT head before giving tPA
Correct Answer: c) IV tissue plasminogen activator - Bradley and Daroff's Neurology in Clinical Practice; Frameworks for Internal Medicine
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