Neuro

Meningitis

• Meningitis is an inflammation of the meninges which are the protective membranes covering the brain and spinal cord.
• It can be caused by infections or non-infectious factors like medications or autoimmune diseases.
• Bacterial meningitis is often severe and life-threatening, requiring urgent antibiotic treatment.
• Viral meningitis is more common and generally less severe, often resolving without specific treatment.
• Fungal and parasitic meningitis is less common, often affecting immunocompromised individuals.
• Aseptic meningitis is caused by non-infectious factors, such as medications or autoimmune conditions.

Meningitis Symptoms

• The classic triad includes fever (sudden onset, often high), severe and persistent headache, and neck stiffness (painful and restricted neck movement or nuchal rigidity).
• Additional symptoms include photophobia (sensitivity to light), altered mental status (confusion, irritability, or drowsiness), nausea and vomiting, seizures (especially in bacterial meningitis), and rash (especially in bacterial meningococcal meningitis).
• Non-blanching petechial or purpuric rash can indicate a more severe infection.
• Symptoms may develop rapidly over hours.

Meningitis Diagnosis and Management

• Patients should be referred to the emergency department.
• Diagnosis involves lumbar puncture to analyze cerebrospinal fluid, with blood tests and imaging as needed.
• Treatment depends on the type, with bacterial forms requiring immediate antibiotics while viral cases may only need supportive care.
• Early identification and treatment is essential to reduce the risk of serious complications like brain damage, hearing loss, or death.

Meningitis Vaccines

• Meningitis vaccines are essential for herd immunity, especially in school and college settings.
• Meningococcal Conjugate Vaccine (MenACWY) protects against Neisseria meningitidis serogroups A, C, W, and Y; it is recommended for adolescents (initial dose at 11-12 years, booster at 16) and high-risk groups (individuals with specific medical conditions, travelers to high-risk areas).
• Serogroup B Meningococcal Vaccine (MenB) protects against Neisseria meningitidis serogroup B; recommended for adolescents and young adults (16-23 years, especially 16-18) and high-risk populations (e.g., immunocompromised individuals, during outbreaks).

Encephalitis

• Encephalitis involves inflammation of the brain tissue.

Causes of Encephalitis

• Viral infections are the most common cause
  • Herpes Simplex Virus (HSV-1 and HSV-2)
  • Varicella-zoster virus (VZV)
  • West Nile virus (WNV)
  • Japanese encephalitis virus (JEV)
  • Rabies virus
• Bacterial and fungal infections are less common, but can include tuberculosis, Lyme disease, and certain fungal infections (especially in immunocompromised patients)
• Autoimmune Encephalitis involves the body's immune system mistakenly attacking brain cells, seen in Anti-NMDA receptor encephalitis.
• Other causes include parasitic infections, toxins, and post-infectious syndromes.

Symptoms of Encephalitis

• Early symptoms: Fever, headache, fatigue, and muscle aches similar to flu-like symptoms.
• Neurological symptoms: Confusion or disorientation, seizures or convulsions, difficulty speaking or understanding language, hallucinations, and loss of consciousness in severe cases.
• Other possible symptoms: Sensitivity to light (photophobia), stiff neck, and nausea or vomiting.

Management of Encephalitis

• Patients should be referred to the emergency department for advanced care.
• Hospitalization is often needed for monitoring and supportive care.
• Treatment includes IV fluids and anti-inflammatory drugs to reduce brain swelling.
• Medications include antivirals, antibiotics, or antifungals based on the etiology; corticosteroids, immunoglobulins, or plasmapheresis is used for autoimmune causes.
• Symptomatic treatment includes anti-seizure medications if seizures are present, and acetaminophen or NSAIDs for pain and fever.
• Rehabilitation involves physical, occupational, and speech therapy for neurological recovery.

Trigeminal Neuralgia

• Primary symptom: Sudden, severe, electric-shock-like facial pain.
• Location: Pain typically affects one side of the face along the trigeminal nerve's branches, usually V2 and V3.
• Triggers: Pain is triggered by activities like chewing, speaking, brushing teeth, or light touch.
• Episodes: Brief attacks lasting from a few seconds to two minutes, with recurrent episodes over days or weeks.

Trigeminal Neuralgia Diagnosis and Treatment

• Diagnosis is based on clinical evaluation including history of facial pain pattern and triggers, physical and neurological exams to rule out other causes, and MRI to rule out underlying causes such as tumors or vascular compression.
• Medications:
  • Anticonvulsants like carbamazepine (first-line) and oxcarbazepine can provide pain relief.
  • Muscle relaxants like baclofen may be added if anticonvulsants alone are insufficient.
  • Surgical options are available for refractory cases, including nerve blocks or injections for temporary relief.

Herpes Zoster (Shingles)

• Reactivation of the varicella-zoster virus (VZV), which also causes chickenpox
• Risk factors include age (especially >50), immunosuppression, and previous chickenpox infection.
• Nerve pain (postherpetic neuralgia) manifests as severe, burning, or stabbing pain persisting after the shingles rash resolves.
• Location: Typically in the area of the previous shingles rash, often thoracic or facial nerves.
• Duration: Can last weeks, months, or even years after rash healing.

Shingles Management

• Antiviral Therapy:
  • Acyclovir, valacyclovir, or famciclovir should be started within 72 hours of rash onset to reduce pain severity and duration.
• Pain Management:
  • Acute pain: NSAIDs, acetaminophen, or opioids may be used for severe cases.
  • Postherpetic neuralgia: Gabapentin, pregabalin, or tricyclic antidepressants may be used.
• Vaccination:
  • Shingrix is recommended for adults 50+ to prevent shingles and postherpetic neuralgia.