neuro

Nervous System with Congenital Neurologic Disorders

Hydrocephalus

  • Definition: Hydrocephalus is a condition characterized by the production of more cerebrospinal fluid (CSF) than can be absorbed, leading to accumulation of excess CSF in the skull.

  • Effects: This excess fluid compresses brain tissue and blood vessels.

    • If the cranial sutures are still open, an infant's head will enlarge beyond normal size.

    • If sutures are closed, increased intracranial pressure (ICP) occurs.

Types of Hydrocephalus

  1. Noncommunicating (Obstructive) Hydrocephalus

    • Causes: Usually results from fetal development abnormalities (e.g., stenosis or atresia).

    • Mechanism: Blockage of CSF flow through the ventricular system, leading to back pressure and dilation of the ventricles, which compresses brain tissue and blood vessels.

  2. Communicating Hydrocephalus

    • Causes: Impaired absorption of CSF through the subarachnoid villi.

    • Mechanism: Results in increased pressure of CSF within the system, with the ability of the skull to expand slightly to relieve pressure.

Developmental Abnormalities as Causes

  • Commonly associated with: Myelomeningocele, Arnold-Chiari malformation.

  • Obstruction can occur due to tumors, infections, or scar tissue at any age.

  • Developmental anomalies are the most frequent cause.

Symptoms and Diagnosis

  • Signs vary with age; symptoms include:

    • Dilated scalp veins.

    • Sluggish pupillary response to light.

    • Sunset sign: white area visible above the pupil.

    • Lethargy, irritability, feeding difficulties.

    • High-pitched/ shrill cry when moved.

  • Treatment: Must be treated promptly to minimize brain damage.

Spina Bifida

  • Definition: A group of neural tube defects characterized by failure of the posterior spinous processes of the vertebrae to fuse, leading to herniation of meninges and spinal cord, resulting in neurological impairment.

  • Common Location: Lumbar area.

Types of Spina Bifida

  1. Spina Bifida Occulta

    • Characteristics: Sinus processes fail to fuse without herniation; often asymptomatic, may show skin signs like a dimple or tuft of hair.

    • Diagnosis: Identified via X-rays or mild neurological signs.

  2. Meningocele

    • Characteristics: Herniation of meninges occurs, forming a sac filled with CSF that does not contain nerve tissue; usually no neurological impairment unless complications arise (sac rupture, infection).

    • Diagnosis: Confirmed through transillumination.

  3. Myelomeningocele

    • Characteristics: Most severe form; includes herniation of the spinal cord and nerves; significant neurological impairment based on the defect's location and extent.

    • Diagnosis: Alpha-fetoprotein (AFP) tests in maternal blood; ultrasound or amniotic fluid analysis.

Treatment and Prognosis

  • Treatment: Surgical repair of the defect; may require ongoing health and occupational/physical therapy.

  • Causes: Multifactorial; linked to genetic predispositions, environmental factors, dietary deficits (like folic acid), and high familial incidence.

Cerebral Palsy

  • Definition: A collection of disorders involving motor impairment from various causes such as genetic mutations, abnormal fetal development, or perinatal brain damage.

Causes of Brain Damage

  • Factors may include:

    • Malformation, hypoxia, trauma, hemorrhage, metabolic disorders, infections.

  • Major Cause: Hypoxia or ischemia due to complications during prenatal care/delivery.

Classifications of Cerebral Palsy

  1. Spastic Cerebral Palsy

    • Origin: Damage to the motor cortex.

    • Symptoms: Paralysis, hyperreflexia, increased muscle tone.

  2. Dyskinetic Cerebral Palsy

    • Origin: Damage to extrapyramidal tracts and basal nuclei.

    • Symptoms: Loss of motor control, involuntary movements (athetosis).

  3. Ataxic Cerebral Palsy

    • Origin: Damage to the cerebellum.

    • Symptoms: Disturbances in balance and coordination.

  4. Mixed Cerebral Palsy

    • Characteristics: Symptoms from more than one type of c.p.

Associated Symptoms

  • Intellectual functioning may vary widely (from normal to severe disabilities).

  • Communication difficulties, seizures, visual or hearing deficits.

  • Treatment: Speech therapy, physical therapy, supportive devices, occupational therapy.

Chronic Degenerative Disorders

Multiple Sclerosis (MS)

  • Definition: Progressive demyelination of neurons in the brain, spinal cord, and cranial nerves.

  • Types: Various types exhibiting different severities and symptoms.

Pathophysiology

  • Loss of myelin disrupts conduction of nerve impulses, affecting motor, sensory, and autonomic functions.

  • Initially involves lesions from inflammatory responses that later become visible plaques.

Symptoms

  • Initial symptoms may include blurred vision, weakness, diplopia, slurred speech (dysarthria), numbness and tingling (paresthesia), and progressive physical impairments.

  • Advanced symptoms: Coordination problems, bladder and bowel dysfunction, fatigue.

Diagnosis and Treatment

  • Diagnosis: MRI used for progression monitoring; no definitive test exists.

  • Treatment: No cure, but therapies for symptom management (physical and occupational therapy).

Parkinson's Disease

  • Definition: Progressive neurodegenerative disorder affecting motor function due to loss of extrapyramidal tract activity.

  • Symptoms: Resting tremors, rigidity, difficulty initiating movements, postural instability.

Stages and Diagnosis

  • Symptoms: Early signs include fatigue and decreased spontaneous movement; advanced symptoms involve tremors, rigidity, and complex movements becoming increasingly difficult.

  • Diagnosis: Primarily clinical; medical history and symptom assessment.

Treatment

  • Options: Dopamine replacement therapy, anticholinergic drugs, physical and occupational therapies to improve function. Regular monitoring for infections.

Amyotrophic Lateral Sclerosis (ALS)

  • Definition: Progressive degeneration of motor neurons in the brain and spinal cord, leading to muscle weakness and atrophy.

  • Causes: Genetic factors linked to various chromosomes; exact cause is unidentified.

Symptoms

  • Early signs: Stumbling, decreased fine motor coordination, and weakness.

  • Complications lead to respiratory failure; cognition remains intact but motor functions severely impaired.

Treatment

  • Management: No specific treatment; medications may slow degeneration. Supportive therapies include respiratory therapy, speech therapy, and occupational therapy.

Myasthenia Gravis

  • Definition: Autoimmune disorder characterized by autoantibodies against acetylcholine receptors leading to skeletal muscle weakness.

  • Symptoms: Face and ocular muscle weakness, dysphagia, and aspiration risk.

Diagnosis and Treatment

  • Diagnosis: Electromyography (EMG), serum antibody testing.

  • Treatment: Anticholinesterase agents, glucocorticoids, immunosuppressants, plasmapheresis, thymectomy.

Huntington's Disease

  • Definition: Inherited disorder characterized by progressive degeneration of the brain with symptoms appearing in midlife.

  • Symptoms: Mood swings, personality changes, and rapid jerky movements of limbs and face.

  • Diagnosis: Detected through DNA analysis; no treatment currently slows disease progression.

Supportive Care

  • Focus on supporting the patient's psychological and physical care needs.