Comprehensive Neurologic and Sensorineural Nursing Assessment and Disorders Study Guide

Cerebellum

The region of the brain responsible for balance, coordination of all voluntary movement, fine motor control, and proprioception.

Glasgow Coma Scale (GCS)

A rapid neurologic screening tool that evaluates eye opening, motor response, and verbal response on a scale from $3$ to $15$, where a score of $8$ or lower typically indicates a coma.

Sclera

The dense, fibrous outer layer known as the visible white of the eye that maintains eyeball shape and protects internal structures.

Organ of Corti

The end organ for hearing located within the inner ear that converts mechanical sound energy into neural activity and differentiates sound frequencies.

Focal Seizure

A seizure that originates in one localized region or hemisphere of the brain.

Generalized Seizure

A seizure that originates and spreads bilaterally across both hemispheres of the brain.

Absence Seizure

A non-convulsive generalized seizure characterized by brief staring episodes, a motionless state, and sudden loss of awareness without overt muscle jerking.

Status Epilepticus

A life-threatening medical emergency defined by continuous seizure activity lasting longer than $5\,minutes$, or recurrent seizures without full recovery of consciousness between episodes.

Kernig's Sign

A diagnostic indicator of meningeal irritation where passive leg extension at the knee with the hip flexed at $90^\circ$ elicits severe hamstring pain and resistance.

Brudzinski's Sign

A diagnostic indicator of meningeal irritation where passive forward flexion of the neck triggers involuntary flexion of the hips and knees.

Bacterial Meningitis

A life-threatening infection of the meninges presenting with severe nuchal rigidity, cloudy CSF, elevated white blood cells, elevated protein, and decreased glucose levels.

Viral Meningitis

A generally self-limiting meningeal infection presenting with clear CSF, mildly elevated protein and white blood cells, and characteristically normal glucose levels.

Bell's Palsy

An acute neuropathy of cranial nerve VII (facial nerve) causing sudden, unilateral facial muscle weakness or paralysis.

Guillain-Barré Syndrome (GBS)

An autoimmune post-infectious attack against peripheral nerve myelin causing symmetric, ascending paralysis starting in the feet and severe loss of deep tendon reflexes.

Amyotrophic Lateral Sclerosis (ALS)

A progressive, fatal motor neuron disease involving degeneration of both upper and lower motor neurons, leading to severe muscle atrophy while retaining intact cognitive and sphincter functions.

Myasthenia Gravis (MG)

An autoimmune disease of the neuromuscular junction in which antibodies destroy acetylcholine receptors, causing fluctuating muscle weakness and fatigability that worsens with activity.

Parkinson's Disease

A neurodegenerative disease caused by dopamine deficiency in the substantia nigra, characterized by the cardinal triad of resting tremor, rigidity, and bradykinesia.

Upper Motor Neurons (UMN)

Neurons originating in the brain and spinal cord whose lesions lead to loss of voluntary control, spasticity, hyperactive reflexes, and a positive Babinski sign without significant muscle atrophy.

Lower Motor Neurons (LMN)

Neurons extending from the spinal cord anterior horn to skeletal muscles whose lesions cause flaccid paralysis, muscle atrophy, decreased muscle tone, and absent or hypoactive reflexes.

Weber Test

A clinical hearing assessment using a vibrating tuning fork placed on the head to evaluate bone conduction and sound lateralization.

Rinne Test

A clinical hearing evaluation using a tuning fork to compare air conduction against bone conduction to differentiate conductive from sensorineural hearing loss.

Lumbar Puncture

A diagnostic needle insertion into the subarachnoid space between $L3-L4$ or $L4-L5$ to measure opening pressure and collect cerebrospinal fluid for analysis.

Amsler Grid

A visual diagnostic grid tool used to detect and monitor central vision alterations related to macular disorders.

Tonometry

A diagnostic ophthalmic test used to measure intraocular pressure inside the eye.

Tensilon Test

A diagnostic procedure for Myasthenia Gravis utilizing edrophonium chloride, where a temporary, dramatic improvement in muscle strength confirms a positive diagnosis.

Lhermitte Sign

A classic symptom of Multiple Sclerosis characterized by an electric shock-like sensation down the spine and limbs triggered by neck flexion.

Sundowning

An acute, transient onset of behavioral agitation and confusion occurring specifically in the late afternoon or early evening in individuals with cognitive impairment.

Delirium

An acute, rapid-onset, and reversible cognitive impairment caused by medical illness, infection, or drug toxicity.

Pronator Drift

A physical assessment sign of an upper motor neuron lesion where an outstretched arm with eyes closed drifts downward and turns inward.

Babinski Reflex

An abnormal neurological reflex in adults where stroke stimulation of the sole causes dorsiflexion of the big toe and fanning of the other toes, indicating central nervous system pathology.