A 55-year-old man comes to the office due to progressive headaches over the past 2 months. The headaches are throbbing, often associated with nausea, and worsen whenever the patient coughs or bears down during a bowel movement. Medical history is significant for episodic migraine without aura. MRI of the brain with gadolinium reveals a cystic mass, as shown in the image below: Which of the following findings is most likely to be seen on physical examination of this patient?

Question

A 55-year-old man comes to the office due to progressive headaches over the past 2 months.  The headaches are throbbing, often associated with nausea, and worsen whenever the patient coughs or bears down during a bowel movement.  Medical history is significant for episodic migraine without aura.  MRI of the brain with gadolinium reveals a cystic mass, as shown in the image below:  Which of the following findings is most likely to be seen on physical examination of this patient?

Quizplus · Accepted Answer

11ec160b_359e_70a6_9249_0569c6babce4_MD0001_00 This patient has an expanding cystic neoplasm (likely a hemangioblastoma) in the left cerebellar hemisphere causing progressive headaches that worsen with Valsalva (maneuver increases intracranial pressure). The cerebellum is the largest structure in the posterior fossa and consists of the vermis at the midline and 2 cerebellar hemispheres. The cerebellar hemispheres are primarily responsible for motor planning and coordination of the ipsilateral extremities via their connections with the lateral descending motor systems (eg, lateral corticospinal tract, rubrospinal tract). Consequently, lesions affecting the left cerebellar hemisphere typically result in left dysdiadochokinesia (impaired rapid alternating movements), limb dysmetria (overshoot/undershoot during targeted movement), and intention tremor (tremor during targeted movement). The cerebellar vermis modulates axial/truncal posture and coordination via connections with the medial descending motor systems (eg, anterior corticospinal, reticulospinal, vestibulospinal, and tectospinal tracts). Lesions to this region result in truncal ataxia (eg, wide-based, unsteady gait). Vertigo and nystagmus may also occur due to disruption of the inferior vermis and the flocculonodular lobe. (Choice B) Horner syndrome (eg, partial ptosis, miosis, anhidrosis) is associated with lesions affecting the ipsilateral lateral hypothalamus or sympathetic tracts in the brainstem (eg, lateral medulla, carotid artery). (Choice C) Oculomotor nerve palsy (mydriasis, complete ptosis, and "down and out" deviation of the eye) may occur with an ipsilateral lesion at the level of the anterior midbrain or midbrain tegmentum. (Choice D) Acute migraine is characterized by throbbing unilateral headache associated with nausea/vomiting, phonophobia, and photophobia. Migraine is unlikely in this patient as his headache worsens with Valsalva (suggestive of increased intracranial pressure) and neuroimaging shows a cerebellar mass. (Choices E, F, and H) Contralateral hemiparesis, hemisensory loss, and/or lower facial droop can occur with cortical, subcortical, or upper brainstem lesions. (Choice G) A unilateral visual pathway lesion beyond the optic chiasm (eg, optic tract, lateral geniculate body, optic radiations, primary visual cortex) can cause contralateral homonymous hemianopia. Educational objective: The cerebellar hemispheres are responsible for motor planning and coordination of the ipsilateral extremities via their connections with the lateral descending motor systems. Consequently, cerebellar hemisphere lesions typically result in ipsilateral dysdiadochokinesia, limb dysmetria, and/or intention tremor. __________ References: Lesion-symptom mapping of the human cerebellum. (http://www.ncbi.nlm.nih.gov/pubmed/18949530)

A 55-Year-Old Man Comes to the Office Due to Progressive