OCC Neurological Assessment & Neuromuscular Medicine Flashcards

Which cranial nerve carries the afferent limb of the corneal reflex?

Answer: CN V ophthalmic branch (V1)

The ophthalmic branch (V1) of the trigeminal nerve (CN V) carries sensory input from the cornea, forming the afferent limb of the corneal reflex.

A patient presents with muscle weakness, hyporeflexia, and fasciculations. These findings are most consistent with:

Answer: Lower motor neuron lesion

Lower motor neuron lesions classically produce weakness, hyporeflexia or areflexia, muscle atrophy, and fasciculations due to denervation.

In osteopathic medicine, somatic dysfunction at the OA-AA complex (C0-C2) can most directly compromise which cranial nerve function via the jugular foramen?

Answer: CN X (vagus)

The vagus nerve (CN X) exits the skull through the jugular foramen, which can be mechanically influenced by somatic dysfunction at the upper cervical region.

Which dermatome covers the lateral forearm, thumb, and index finger?

Answer: C6

The C6 dermatome supplies the lateral forearm, thumb, and index finger, and is commonly tested in carpal tunnel syndrome evaluation.

On MRI, multiple sclerosis most characteristically shows lesions in which location?

Answer: Periventricular white matter plaques

MS causes demyelinating plaques predominantly in periventricular white matter, the corpus callosum, and cerebellum, best seen on T2/FLAIR MRI sequences.

A positive Babinski sign (upgoing plantar response) indicates a lesion of which neural pathway?

Answer: Corticospinal (pyramidal) tract

The Babinski sign is a classic upper motor neuron sign indicating disruption of the corticospinal tract, releasing primitive reflexes normally suppressed by descending inhibition.

According to osteopathic neurological theory, a 'facilitated segment' is characterized by:

Answer: Spinal cord hyperreactivity due to sustained afferent input lowering the firing threshold

A facilitated segment is a spinal cord level with a lowered neural firing threshold caused by sustained afferent input, making it hyperreactive to all stimuli.