7.2 Neurologic Disorders & Management

Seizure Disorders

Seizures are classified as focal (beginning in one hemisphere, with or without impaired awareness, sometimes progressing to bilateral tonic-clonic) or generalized (involving both hemispheres from onset, including tonic-clonic and absence seizures). A generalized tonic-clonic seizure has a tonic phase (rigid stiffening, possible cyanosis and incontinence) followed by a clonic phase (rhythmic jerking), then a postictal period of confusion and deep sleep.

Seizure precautions for at-risk inpatients: padded side rails, suction equipment and an oral airway at the bedside, side rails up, bed in lowest position, and oxygen available. During a seizure, the priorities are protection and airway — stay with the patient, lower to the floor or protect the head, turn to a side-lying position to prevent aspiration, loosen restrictive clothing, and time the seizure. Never force anything into the mouth, never restrain the limbs, and suction only after the seizure ends. Document onset, duration, movements, eye deviation, incontinence, and postictal behavior.

Status epilepticus is a seizure lasting 5 minutes or longer, or repeated seizures without regaining consciousness between them. It is a medical emergency because sustained seizure activity causes hypoxia and neuronal injury. First-line treatment is an intravenous benzodiazepine — lorazepam 4 mg IV (0.1 mg/kg, up to 4 mg per dose, may repeat once) — followed by a loading dose of a longer-acting agent such as fosphenytoin, levetiracetam, or valproate. Establish IV access, give oxygen, check glucose (hypoglycemia is a reversible cause), and prepare for airway support.

Antiseizure Medication Pearls

• Phenytoin: therapeutic serum level 10-20 mcg/mL; toxicity (nystagmus, ataxia, diplopia, sedation) appears above 20. Chronic effects include gingival hyperplasia (teach meticulous oral hygiene) and hirsutism. IV phenytoin must infuse no faster than 50 mg/minute (risk of hypotension and dysrhythmias) and is compatible only with normal saline — it precipitates in dextrose. Fosphenytoin is the safer IV prodrug. Never stop antiseizure drugs abruptly; withdrawal precipitates seizures.
• Levetiracetam (Keppra): broad-spectrum, minimal drug interactions, no routine level monitoring, renal dosing. Watch for behavioral changes — irritability, agitation, depression — especially early in therapy.

Increased Intracranial Pressure

Normal intracranial pressure (ICP) is 5-15 mm Hg; sustained pressure above 20 mm Hg requires treatment. The earliest sign of increased ICP is a change in level of consciousness — restlessness, lethargy, or subtle confusion. Later signs include projectile vomiting, ipsilateral pupil dilation, and papilledema. Cushing's triad — rising systolic blood pressure with widened pulse pressure, bradycardia, and irregular respirations — is a late sign of impending herniation and demands immediate intervention.

Nursing care to lower ICP:

• Elevate the head of bed to 30 degrees and keep the head and neck in a neutral midline position to promote venous drainage; avoid hip flexion and neck rotation or flexion
• Avoid clustering care — space activities, because each intervention transiently raises ICP; allow rest between procedures
• Prevent anything that raises ICP: suction only when needed with pre-oxygenation, avoid coughing and Valsalva (stool softeners, no straining), keep the environment calm and quiet, avoid fever
• Mannitol, an osmotic diuretic, pulls fluid from brain tissue into the vasculature; give through a filter needle (crystallizes), monitor serum osmolality, electrolytes, and fluid status — hypovolemia drops cerebral perfusion, and rebound edema can occur. Foley catheter output is tracked closely
• Controlled hyperventilation (PaCO2 30-35 mm Hg) is reserved for acute herniation as a temporary bridge; prolonged hypocapnia worsens cerebral ischemia

Spinal Cord Injury: Two Shocks and One Emergency

Spinal shock is a transient, physiologic loss of all reflexes, sensation, and motor function below the injury, with flaccid paralysis; it resolves over days to weeks as reflexes gradually return. Neurogenic shock (typically with injuries at T6 and above) is a hemodynamic problem from loss of sympathetic tone: hypotension with bradycardia and warm, dry skin — unlike hypovolemic shock, which pairs hypotension with tachycardia and cold, clammy skin. Treatment is careful fluids and vasopressors; avoid fluid overload.

Autonomic dysreflexia (hyperreflexia) is a life-threatening emergency in patients with injuries at T6 or above, occurring any time after spinal shock resolves. A noxious stimulus below the injury triggers massive unopposed sympathetic outflow: sudden severe hypertension, pounding headache, flushing and sweating above the lesion, pale cool skin below, nasal congestion, blurred vision, and reflex bradycardia. The most common triggers are a distended bladder (kinked or blocked catheter) and bowel impaction. The response, in order:

1. Sit the patient upright immediately (lowers blood pressure orthostatically) and loosen constrictive clothing
2. Check blood pressure frequently
3. Find and remove the trigger — check the catheter for kinks first, irrigate or replace as ordered; if the bladder is not the cause, assess for fecal impaction (use anesthetic jelly before disimpaction to avoid worsening the reflex)
4. Give rapid-acting antihypertensives as ordered (nitroglycerin paste, nifedipine)

Prevention teaching: regular bladder and bowel programs and skin checks for pressure injury.

Meningitis

Bacterial meningitis (commonly Neisseria meningitidis or Streptococcus pneumoniae) is a medical emergency. Classic findings are fever, severe headache, nuchal rigidity (stiff neck), photophobia, and altered mental status. Meningeal irritation signs include Kernig's sign (pain and resistance when the knee is extended with the hip flexed) and Brudzinski's sign (involuntary hip and knee flexion when the neck is flexed). Meningococcemia produces a petechial or purpuric rash that does not blanch. Key nursing actions:

• Place the patient in droplet precautions (suspected N. meningitidis or H. influenzae) for the first 24 hours of effective antibiotics; private room, mask for anyone entering
• Antibiotics must start promptly — do not delay them waiting for lumbar puncture or CT if those are delayed
• Cerebrospinal fluid in bacterial meningitis: cloudy, high white blood cells (neutrophils), high protein, low glucose; viral meningitis: clear fluid, lymphocytes, normal glucose
• Institute seizure precautions, keep the room dark and quiet, and monitor for increased ICP and syndrome of inappropriate antidiuretic hormone (SIADH)

Chronic Neurologic Diseases

Multiple sclerosis (MS) is autoimmune demyelination of the central nervous system; relapsing-remitting is the most common course. Symptoms include fatigue, spasticity, visual changes (optic neuritis), diplopia, and sensory loss. Management: disease-modifying therapy (interferon beta, glatiramer), baclofen for spasticity, energy conservation with planned rest, bladder and bowel programs, and avoiding heat — hot weather and hot showers worsen conduction through demyelinated nerves (Uhthoff's phenomenon). Teach fall prevention and promote independence.

Parkinson's disease is dopamine deficiency in the basal ganglia producing the classic triad: resting "pill-rolling" tremor, cogwheel rigidity, and bradykinesia, plus a shuffling gait and masked facies. Levodopa/carbidopa is the mainstay; pearls include giving it on an empty stomach (absorption competes with dietary protein — avoid high-protein meals near doses), warning that dark urine and sweat are harmless, watching for dyskinesias and orthostatic hypotension (fall risk), and never stopping abruptly (risk of a neuroleptic malignant-like syndrome). Encourage exercise and aspiration precautions for dysphagia.

Myasthenia gravis is autoimmune antibody attack on acetylcholine receptors, causing fatigable weakness that worsens with activity and improves with rest — ptosis, diplopia, dysphagia, and proximal limb weakness. Diagnosis uses the edrophonium (Tensilon) test (transient improvement is positive); treatment is anticholinesterases such as pyridostigmine, taken on schedule before meals to aid chewing and swallowing. Distinguish the two crises:

Both crises threaten the airway and ventilation — monitor respiratory effort and negative inspiratory force. Teach patients to avoid drugs that worsen myasthenia: aminoglycosides, fluoroquinolones, beta-blockers, and magnesium.