Neurological Disorders

Neurological Disorders

In the acute clinical setting, neurological disorders demand rapid assessment, precise intervention, and continuous monitoring. The Dubai Health Authority (DHA) exam frequently tests these topics because delays in recognizing neurological deterioration can lead to permanent brain damage or death. Nurses must be experts in managing strokes, seizures, increased intracranial pressure (ICP), and head trauma.

Stroke (Cerebrovascular Accident)

A Cerebrovascular Accident (CVA), or stroke, is a clinical emergency caused by a disruption of blood flow to the brain, resulting in neuronal ischemia and necrosis. Strokes are classified into two main types:

• Ischemic Stroke (87% of cases): Caused by an occlusion of a cerebral artery due to a thrombus or embolus.
• Hemorrhagic Stroke (13% of cases): Caused by a rupture of a blood vessel leading to intracerebral or subarachnoid bleeding, which increases pressure on the surrounding brain tissue.

Clinical Assessment and Diagnosis

Immediate recognition is achieved using the FAST screening tool:

• F - Face Drooping: Ask the patient to smile; check for asymmetry.
• A - Arm Weakness: Ask the patient to raise both arms; check if one drifts downward.
• S - Speech Difficulty: Ask the patient to repeat a simple sentence; check for slurring or difficulty.
• T - Time to call emergency services: Establish the exact Last Known Normal (LKN) time, which is critical for determining treatment eligibility.

In the emergency department, the National Institutes of Health Stroke Scale (NIHSS) is used to quantify neurological impairment. The gold standard initial diagnostic test is a non-contrast Head CT scan to quickly rule out a hemorrhagic stroke before any thrombolytic therapy is initiated.

Acute Nursing Interventions

1. Thrombolytic Therapy: For eligible patients with ischemic stroke, recombinant tissue plasminogen activator (rtPA) is administered intravenously. The clinical window is 3 to 4.5 hours from the Last Known Normal time.
   • Inclusion Criteria: Age >= 18, measurable neurological deficit, onset of symptoms < 4.5 hours.
   • Absolute Contraindications: Active internal bleeding, history of hemorrhagic stroke, recent intracranial or intraspinal surgery (within 3 months), head trauma, platelets < 100,000/mm³, or uncontrolled blood pressure (Systolic BP > 185 mmHg or Diastolic BP > 110 mmHg).
2. Blood Pressure Management:
   • Ischemic Stroke (rtPA candidate): Maintain blood pressure below 180/105 mmHg during and for 24 hours post-infusion to prevent hemorrhagic conversion.
   • Ischemic Stroke (non-rtPA candidate): Allow permissive hypertension (Systolic BP up to 220 mmHg or Diastolic BP up to 120 mmHg) to maintain perfusion to the ischemic penumbra, unless there is end-organ damage.
   • Hemorrhagic Stroke: Maintain strict blood pressure control (often keeping Systolic BP < 140 mmHg) to prevent ongoing bleeding.
3. Positioning: Elevate the Head of the Bed (HOB) to 30 degrees and keep the head in a neutral, midline position. This facilitates venous drainage from the brain and reduces intracranial pressure.
4. Aspiration Prevention: Keep the patient strictly NPO (Nothing by Mouth) until a formal bedside swallow screening is completed by the nurse or speech therapist. Dysphagia is highly common after a stroke and poses a significant risk for aspiration pneumonia.

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Seizures and Status Epilepticus

A seizure is a sudden, uncontrolled electrical disturbance in the brain that can cause changes in behavior, movements, feelings, and levels of consciousness. Status epilepticus is a continuous state of seizure activity lasting more than 5 minutes, or consecutive seizures occurring without the patient regaining consciousness in between. It is a neurological emergency that can lead to cerebral hypoxia, hyperthermia, and rhabdomyolysis.

Phases of a Seizure

• Aura: A sensory warning sign preceding a seizure (e.g., visual disturbances, unusual smell, or metallic taste).
• Ictal Phase: The active phase of the seizure characterized by motor activity (tonic-clonic contractions), autonomic changes, or altered awareness.
• Postictal Phase: The recovery phase following the seizure. The patient is typically lethargic, confused, complains of a headache, and has no memory of the event.

Acute Nursing Management During a Seizure (Ictal Phase)

During a seizure, the nurse's primary goals are maintaining a patent airway and ensuring patient safety.

• Turn the patient onto their side: This allows saliva and secretions to drain, preventing airway obstruction and aspiration.
• Protect the head: Place a folded towel or pillow under the head, or guide the patient to the floor if they are out of bed.
• Do NOT insert anything into the mouth: Inserting padded tongue blades, airways, or fingers can cause dental fractures, oral trauma, or worsen airway obstruction.
• Do NOT restrain the patient: Allow the muscle contractions to occur naturally; trying to hold the patient down can lead to musculoskeletal injury or fractures.
• Loosen clothing: Loosen tight ties, collars, or clothing around the neck.
• Clear the environment: Move hard or sharp objects away from the patient's immediate area.
• Document and Observe: Note the time of onset, duration of the seizure, body parts involved, pupil response, and characteristics of the postictal phase.

Pharmacological Interventions

1. First-Line (Emergency): Intravenous (IV) benzodiazepines are administered immediately to terminate the seizure. The preferred medications are lorazepam (Ativan) or diazepam (Valium). If IV access is unavailable, rectal diazepam gel or intramuscular midazolam can be used.
2. Second-Line (Maintenance): Antiepileptic drugs (AEDs) are administered to prevent recurrence. These include phenytoin (Dilantin), fosphenytoin, or levetiracetam (Keppra).
   • Phenytoin Safety: Must only be diluted in Normal Saline (0.9% NaCl); mixing it with dextrose solutions causes precipitation. The administration rate must not exceed 50 mg/minute to prevent severe hypotension and cardiac arrhythmias. Regularly monitor therapeutic drug levels (10-20 mcg/mL).

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Increased Intracranial Pressure (ICP)

The Monro-Kellie Doctrine states that the cranial vault is a rigid, closed sphere containing three non-compressible components: brain tissue (80%), blood (10%), and cerebrospinal fluid (CSF) (10%). If the volume of any of these components increases, the volume of the others must decrease to maintain a normal ICP of 5 to 15 mmHg. Once compensatory mechanisms fail, ICP rises rapidly, leading to decreased cerebral perfusion pressure (CPP) and potential brain herniation.

Nursing Interventions to Manage ICP

• Elevate the Head of the Bed: Maintain the HOB at 30 degrees. Avoid neck flexion, neck rotation, or extreme hip flexion, as these positions compress the internal jugular veins and impede venous outflow from the brain.
• Reduce Stimuli: Keep the room dim, quiet, and cool. Minimize noise, limit visitors, and avoid disturbing the patient unnecessarily.
• Cluster Care Caution: While clustering nursing care is standard, for patients with high ICP, care activities should be spaced out to allow the ICP to return to baseline between tasks.
• Prevent Valsalva Maneuver: Administer prescribed stool softeners to prevent straining during defecation. Avoid encouraging coughing or deep breathing; instead, instruct the patient to exhale when turning.
• Osmotic Therapy: Administer mannitol (Osmitrol), an osmotic diuretic, or hypertonic saline (e.g., 3% NaCl).
  • Mannitol Administration: Mannitol draws water out of brain tissue into the vascular space. It must be administered through an in-line filter needle because it easily crystallizes at room temperature. Check the vial for crystals before infusing. Monitor serum osmolality (maintain < 320 mOsm/kg) and strict hourly intake/output.

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Head Trauma and Intracranial Hematomas

Traumatic Brain Injury (TBI) can result in primary and secondary brain injury. A major consequence of head trauma is the formation of intracranial hematomas, which act as space-occupying lesions.

Epidural vs. Subdural Hematoma

• Epidural Hematoma: An accumulation of blood between the skull and the dura mater. It is usually caused by an arterial tear (most commonly the middle meningeal artery), often secondary to a temporal bone fracture.
  • Classic Presentation: Brief initial loss of consciousness, followed by a temporary lucid interval (where the patient appears awake and fully coherent), followed by a rapid, catastrophic neurological deterioration (unconsciousness, pupillary dilation, decerebrate posturing). It is a surgical emergency requiring immediate craniotomy and hematoma evacuation.
• Subdural Hematoma: An accumulation of blood between the dura mater and the arachnoid membrane. It is usually caused by a venous tear in the bridging veins.
  • Presentation: Bleeding is slower. It can present as acute (within 24-48 hours), subacute (2 days to 2 weeks), or chronic (weeks to months, common in older adults and individuals with alcohol use disorder due to brain atrophy).

Glasgow Coma Scale (GCS)

Nurses must frequently assess TBI patients using the GCS. The scale scores three behaviors:

1. Eye Opening (Score 1 - 4): Spontaneous (4), to speech (3), to pain (2), none (1).
2. Verbal Response (Score 1 - 5): Oriented (5), confused (4), inappropriate words (3), incomprehensible sounds (2), none (1).
3. Motor Response (Score 1 - 6): Obeys commands (6), localizes pain (5), withdraws from pain (4), abnormal flexion/decorticate (3), abnormal extension/decerebrate (2), none (1).

Clinical Rule: A total score ranges from 3 to 15. A score of 8 or less indicates a state of coma and severe brain injury, requiring immediate endotracheal intubation to protect the patient's airway ("GCS of 8, intubate").