Common Neurological Disorders: Causes and Symptoms
Headaches
Headaches can have many causes, including:
- Brain cell injury
- Infections of the eyes, nose, and sinuses
- Tension headaches associated with stress, fatigue, or anxiety
- Migraines
Most headaches do not require special treatment. If the cause is unknown, analgesics or tranquilizers may be used, particularly for tension headaches.
Stroke
Stroke is the most common abnormality of the brain. It can be:
- Ischemic: Due to decreased blood flow.
- Hemorrhagic: Due to arteriosclerosis or the rupture of a blood vessel in the brain.
Neurological symptoms (such as weakness, paralysis, or difficulty speaking) may be transient, very severe, or fatal.
Parkinson’s Disease
This is a progressive impairment of the central nervous system. The cause is unknown, but environmental toxic factors are suspected influences. Changes occur in the substantia nigra and basal ganglia of the midbrain, producing a decrease in the secretion of dopamine, leading to a predominance of acetylcholine. It is characterized by:
- Tremor
- Rigidity
- Bradykinesia (slowness of movement), making habitual activities difficult.
Treatment is based on L-dopa and drugs that reduce acetylcholine levels.
Multiple Sclerosis (MS)
MS is a progressive disease characterized by the destruction of myelin in the central nervous system. When the myelin is damaged, nerve impulses do not circulate well, leading to neurological deficits. The causal agent of MS is unclear. The specific nervous system disorder depends on where the demyelinating plaques appear. Therefore, symptoms can be very varied, including:
- Loss of vision
- Difficulty in coordination
- Tremor
- Fatigue (an almost constant symptom in these patients)
Main Neurotransmitters
Key chemicals involved in nerve signal transmission include:
- Acetylcholine: Can be excitatory or inhibitory depending on the neuron.
- Glutamate: Generally excitatory.
- Dopamine: Found in locomotor pathways; its absence is linked to Parkinson’s disease.
- Endorphin: Inhibitor of pain sensation.
- GABA (Gamma-Aminobutyric Acid): Generally inhibitory.
- Histamine: Generally excitatory.
- Serotonin: Generally inhibitory; interacts with mood states.
Epilepsy
Epilepsy is characterized by periodic, short, and recurrent attacks of motor, sensory, or psychological malfunction. Typical seizures present with loss of consciousness, contractions of skeletal muscles, and sensory alterations. Attacks begin with abnormal synchronous electrical discharges from millions of brain neurons. The cause is most often unknown but may result from metabolic disorders, infections, toxins, or vascular disorders. Treatment involves drugs that depress neuronal excitability.
Spinal Cord Injury
The spinal cord may be injured by compression secondary to various causes, such as tumors, herniated discs, or trauma. Depending on the location and extent of the lesion, paralysis may occur. Paralysis is the total loss of voluntary motor function secondary to nervous or muscular tissue injury. Types of paralysis include:
- Monoplegia: Paralysis of one limb.
- Diplegia: Paralysis of two limbs (usually the legs).
- Paraplegia: Paralysis of the lower limbs.
- Quadriplegia: Paralysis of all four limbs.
- Hemiplegia: Paralysis of the upper and lower limb on the same side.
ALS (Amyotrophic Lateral Sclerosis)
ALS is a neuromuscular disease of unknown origin, affecting the neurons that provide information to the muscles for movement. The defect appears in the motor neurons, specifically in the anterior horn of the spinal cord. The first symptoms of ALS often include:
- Progressive loss of strength in the upper extremities (noticeable in activities like lifting weights or turning a tap).
- Decreased muscle mass in arms and hands.
- Speech disorders (e.g., nasal voice, difficulty moving the tongue) due to loss of strength in larynx and tongue muscles.