A 65-year-old man is brought to the emergency department due to acute onset of a severe headache and dizziness. He describes it as a throbbing that localizes to the back of his head, with associated vertigo and mild nausea. The patient has a past medical history of type 2 diabetes mellitus, hypertension, chronic obstructive pulmonary disease, and a recent diagnosis of lung adenocarcinoma. He has smoked 1-2 packs of cigarettes daily for the past 30 years. His temperature is 36.7 C (98 F), blood pressure is 170/96 mm Hg, pulse is 80/min, and respirations are 14/min. Noncontrast head CT reveals an acute hemorrhage in the cerebellar vermis without mass effect or midline shift. Which of the following neurologic findings is most likely to be present during this patient's physical examination?

Question

A 65-year-old man is brought to the emergency department due to acute onset of a severe headache and dizziness.  He describes it as a throbbing that localizes to the back of his head, with associated vertigo and mild nausea.  The patient has a past medical history of type 2 diabetes mellitus, hypertension, chronic obstructive pulmonary disease, and a recent diagnosis of lung adenocarcinoma.  He has smoked 1-2 packs of cigarettes daily for the past 30 years.  His temperature is 36.7 C (98 F), blood pressure is 170/96 mm Hg, pulse is 80/min, and respirations are 14/min.  Noncontrast head CT reveals an acute hemorrhage in the cerebellar vermis without mass effect or midline shift.  Which of the following neurologic findings is most likely to be present during this patient's physical examination?

Quizplus · Accepted Answer

11ec160b_39c3_d81f_9249_bd81d6f08e2a_MD0001_00 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). Consequently, acute lesions to this region (eg, due to hemorrhage) typically result in truncal ataxia, characterized by a wide-based, unsteady gait. Patients may also develop vertigo and nystagmus due to involvement of the inferior vermis and the flocculonodular lobe (vestibulocerebellum), which modulate balance and ocular movements via connections with the vestibular nuclei and medial longitudinal fasciculus. Other features of cerebellar hemorrhage include nausea and occipital headache. Most cases are caused by hypertensive vasculopathy, but this patient's recent diagnosis of lung adenocarcinoma should also raise concern for hemorrhagic metastasis. (Choice A) Complete ptosis from central lesions may result from injury to the oculomotor nerve fibers within the upper midbrain and is typically associated with contralateral hemiparesis due to adjacent corticospinal tract involvement (eg, Weber syndrome). (Choice B) Oropharyngeal dysphagia is usually associated with lesions in the brainstem due to involvement of cranial nerves IX, X, and XII, and/or their nuclei. Cerebral cortical and subcortical lesions affecting the descending corticobulbar tracts may also lead to oropharyngeal dysphagia. (Choice C) Hemiparesis results from lesions affecting the corticospinal tracts in the cerebral subcortical white matter and brainstem. Cerebellar lesions do not cause pyramidal tract signs or hemiparesis. (Choice D) Limb dysmetria (overshoot/undershoot during targeted movement) is usually associated with lesions affecting the cerebellar hemispheres due to involvement of the lateral descending motor systems (eg, lateral corticospinal tract, rubrospinal tract). Hemispheric cerebellar lesions may also cause tremor during goal-directed activity (intention tremor). (Choice E) Resting tremor is typically associated with parkinsonism due to damage of the substantia nigra and its projections to the striatum. Rubral tremor occurs at rest and during goal-directed activity and is associated with combined lesions to the midbrain, substantia nigra, and superior cerebellar peduncle due to disruption of cerebellothalamic pathways. Educational objective: Acute lesions to the cerebellar vermis typically cause truncal and gait ataxia due to impaired modulation of the medial-descending motor systems. Involvement of the lower vermis and the flocculonodular lobe also causes vertigo/nystagmus due to dysregulation of the vestibular nuclear complex. __________ References: Alternating skew deviation due to hemorrhage in the cerebellar vermis. (http://www.ncbi.nlm.nih.gov/pubmed/23037477) Acute spontaneous cerebellar hemorrhage. (http://www.ncbi.nlm.nih.gov/pubmed/3735446) Positional vertigo and the cerebellar vermis. (http://www.ncbi.nlm.nih.gov/pubmed/6538309)

A 65-Year-Old Man Is Brought to the Emergency Department Due