Neurology

Neurology Indian Medical PG Question 1: A 45-year-old man presents with weakness in his right arm and slurred speech that started suddenly 2 hours ago. Which diagnostic test is most appropriate to confirm the diagnosis?

• A. Nerve conduction study
• B. Electroencephalogram (EEG)
• C. CT scan of the head (Correct Answer)
• D. MRI of the spine

Neurology Explanation: ***CT scan of the head*** - A **CT scan of the head** is the most appropriate initial diagnostic test for sudden onset neurological deficits like **weakness** and **slurred speech** to rule out an acute intracranial hemorrhage or ischemic stroke [1]. - It is rapid, widely available, and crucial for guiding immediate management decisions [1]. *Nerve conduction study* - **Nerve conduction studies** are used to evaluate the function of peripheral nerves and muscles, typically for conditions like **neuropathy** or myasthenia gravis, which are not suggested by the acute, focal central nervous system symptoms. - These studies would not provide time-sensitive information about an acute stroke or hemisphere. *Electroencephalogram (EEG)* - An **EEG** measures electrical activity in the brain and is primarily used to diagnose **seizure disorders**, sleep disorders, or assess altered mental status. - It is not indicated for the initial evaluation of sudden focal neurological deficits such as stroke. *MRI of the spine* - An **MRI of the spine** is used to visualize the spinal cord and surrounding structures to diagnose conditions like **spinal cord compression**, disc herniation, or myelitis. - The patient's symptoms of right arm weakness and slurred speech clearly localize to the brain, not the spine.

Neurology Indian Medical PG Question 2: Most useful test to differentiate upper from lower motor neuron lesion?

• A. Deep tendon reflexes (Correct Answer)
• B. Muscle tone
• C. Hoffman sign
• D. EMG changes

Neurology Explanation: ***Deep tendon reflexes*** - **Upper motor neuron (UMN)** lesions typically cause **hyperreflexia** due to loss of inhibitory input [1]. - **Lower motor neuron (LMN)** lesions typically result in **hyporeflexia or areflexia** due to damage to the reflex arc itself. *Muscle tone* - **UMN lesions** often lead to **spasticity** (velocity-dependent increase in tone) [2], [3]. - **LMN lesions** result in **flaccidity** or decreased tone due to loss of muscle innervation [1]. While helpful, reflex changes are more consistently discriminatory. *Hoffman sign* - The **Hoffman sign** is a pathological reflex used to detect **cervical myelopathy** or other **UMN dysfunction**, particularly in the upper limbs. - Its presence indicates UMN involvement, but its absence does not definitively rule out a UMN lesion elsewhere or confirm an LMN lesion. *EMG changes* - **Electromyography (EMG)** can help differentiate UMN from LMN lesions by evaluating nerve and muscle activity, showing features like **fibrillation potentials** and **fasciculations** in LMN lesions [1]. - However, it is an investigative test, and clinically, deep tendon reflexes provide a rapid and often sufficient distinction at the bedside.

Neurology Indian Medical PG Question 3: In an accident case, after the arrival of medical team, all should be done in early management except;

• A. Glasgow coma scale
• B. Check BP (Correct Answer)
• C. Stabilization of cervical vertebrae
• D. Check Respiration

Neurology Explanation: ***Check BP*** - In the **immediate/early management** of trauma (primary survey), while circulation assessment is crucial, the **initial assessment of circulation** focuses on: - **Pulse rate and quality** (radial, carotid) - **Capillary refill time** - **Skin color and temperature** - **Active hemorrhage control** - **Formal blood pressure measurement** with a cuff, while important, is typically recorded during or after these rapid initial assessments, as it takes more time to obtain an accurate reading. - In the context of this question, among the four options listed, BP measurement is relatively less immediate compared to the other life-saving priorities (airway protection, breathing assessment, C-spine stabilization, and GCS). - **Note:** This is a nuanced distinction - BP is assessed during primary survey, but the other three options have more immediate life-threatening implications if not addressed. *Glasgow coma scale* - **GCS assessment** is part of the **"D" (Disability)** step in the ATLS primary survey. - It is performed early to assess neurological status and level of consciousness. - GCS <8 indicates need for **definitive airway protection** (intubation). - This is a critical early assessment that guides immediate management decisions. *Stabilization of cervical vertebrae* - **C-spine immobilization** is part of the **"A" (Airway)** step - "Airway with cervical spine protection." - It is performed **simultaneously** with airway assessment using a **rigid cervical collar**. - This is the **first priority** in trauma management to prevent secondary spinal cord injury. - All trauma patients should be assumed to have C-spine injury until proven otherwise. *Check Respiration* - **Respiratory assessment** is part of the **"B" (Breathing)** step in the ATLS primary survey. - This involves checking: - **Respiratory rate and pattern** - **Chest wall movement** - **Air entry bilaterally** - **Signs of tension pneumothorax or flail chest** - This is an immediate life-saving priority and must be assessed early.

Neurology Indian Medical PG Question 4: Which vessel is most likely damaged in an extradural (epidural) hemorrhage?

• A. Basilar artery
• B. Vertebral artery
• C. Middle meningeal artery (Correct Answer)
• D. Anterior cerebral artery

Neurology Explanation: Middle meningeal artery - An extradural (epidural) hemorrhage often results from head trauma, especially to the temporal region, which can cause a fracture across the course of the middle meningeal artery [1]. - This artery runs in a groove on the inner surface of the temporal bone, making it vulnerable to laceration during trauma [1]. Basilar artery - The basilar artery is located at the base of the brainstem and is a common site for strokes, but not typically involved in an extradural hemorrhage. - Damage to the basilar artery usually leads to subarachnoid hemorrhage or ischemic stroke, not an epidural hematoma. Vertebral artery - The vertebral arteries ascend through the cervical vertebrae and join to form the basilar artery, supplying the posterior circulation of the brain. - Damage to these arteries is typically associated with neck trauma or dissection, leading to subarachnoid hemorrhage or ischemia, not an epidural hemorrhage. Anterior cerebral artery - The anterior cerebral artery supplies the frontal lobes and medial aspects of the cerebral hemispheres. - While it can be involved in subarachnoid or intracranial hemorrhages from aneurysm rupture or trauma, it is not the typical source of an epidural hematoma.

Neurology Indian Medical PG Question 5: Therapeutic drug monitoring is done for:

• A. Aspirin
• B. Heparin
• C. Phenytoin (Correct Answer)
• D. Metformin

Neurology Explanation: ***Phenytoin*** - **Phenytoin** has a **narrow therapeutic window**, meaning the difference between an effective and a toxic dose is small, necessitating close monitoring. - Its **variable absorption** and **nonlinear pharmacokinetics** (saturable metabolism) make individual dosing adjustments critical to maintain therapeutic levels and avoid toxicity. *Aspirin* - **Aspirin** is generally not monitored via plasma levels for its analgesic or antiplatelet effects, as its therapeutic effects are often observed at doses where plasma monitoring is not practical or necessary. - Its primary therapeutic use as an **antiplatelet agent** is evaluated by clinical outcomes rather than drug concentration. *Heparin* - **Heparin** is monitored using coagulation tests like **aPTT (activated partial thromboplastin time)** or anti-Xa levels to assess its anticoagulant effect, not direct drug concentration. - Therapeutic drug monitoring for heparin focuses on its **pharmacodynamic effects** on the clotting cascade rather than its absolute plasma concentration. *Metformin* - **Metformin** has a relatively **wide therapeutic index** and its efficacy is primarily measured by reductions in blood glucose and HbA1c, not by plasma drug concentrations. - It is excreted largely unchanged by the kidneys, and dose adjustments are typically made based on **renal function** and glycemic control.

Neurology Flashcard 1 of 5

Question: Kurtzke's early disablity status score is used for grading _____

Answer: multiple sclerosis

Neurology Flashcard 2 of 5

Question: _____ (dementia or delirium) is associated with a normal pattern on EEG

Answer: Dementia

Neurology Flashcard 3 of 5

Question: Multiple sclerosis is associated with a sensation of an _____ running down the spine upon neck flexion (Lhermitte phenomenon)

Answer: electric shock

Neurology Flashcard 4 of 5

Question: _____ disease is characterized by periodic sharp wave complexes on EEG

Answer: Creutzfeldt-Jakob

Neurology Flashcard 5 of 5

Question: Dementia with gait disturbances and rigidity would point you to the diagnosis of _____

Answer: dementia with lewy bodies