Nervous System Disorder Diagnosis

Diagnosing Neurological Disorders

• The symptoms of a nervous system problem depend on which area of the nervous system is involved and what is causing the problem.
• Diagnosis involves:
  • Chief complaints and onset
  • History of present illness
  • Review of patient-specific information (past, systems, family, social history)
  • Neurological examination
  • Assessment of the cause of the patient's symptoms
  • Diagnostic tests

Neurological Examination

• Levels of consciousness
• Mental status examination
• Special cerebral functions
• Cranial nerve function
• Motor function
• Sensory function
• Cerebellar function
• Gait
• Reflexes and tests

Association of Neurological Disorders

• Blood supply problems (vascular disorders)
• Injuries (trauma), especially injuries to the head and spinal cord
• Problems present at birth (congenital)
• Mental health problems, such as anxiety disorders, depression, or psychosis
• Exposure to toxins, such as carbon monoxide, arsenic, or lead
• Problems that cause a gradual loss of function (degenerative)
• Overuse of or withdrawal from prescription and nonprescription medicines, illegal drugs, or alcohol
• Brain tumor (spinal cord, membranes)
• Infection disease
• Other conditions (endocrine disorders complications, electrolyte problems, Vitamin deficiency)

Cranial Nerve Reflexes

• Pupillary light reflex: CN II, CN III, upper midbrain
• Corneal reflex: CN V, CN VII, lower midbrain to upper pons
• Oculocephalic reflex: CN VIII, CN III, IV, VI, upper midbrain to lower pons
• Gag reflex: CN IX, CN X, medulla
• Cough reflex: CN X, CN X, medulla to cervical spinal cord

Motor Examination

• Decorticate posturing: indicates hemispheric damage with preservation of motor centers in the upper brain stem
• Decerebrate posturing: indicates damage to upper brain stem motor centers, which facilitate flexion, and only lower brain stem centers (vestibulospinal tract, reticulospinal tract) are responding to sensory stimuli

Respiratory Patterns

• Helpful in localizing area of CNS dysfunction

CN V Examination

• Corneal reflex
• Masticatory muscle function
• Wasting and thinning of temporalis muscle
• Jaw deviation to the weak side

CN V Disorders/Syndromes

• Sensory trigeminal neuropathy: progressive, painless loss of trigeminal sensation
• Mental neuropathy (numb chin syndrome): caused by a lesion of the mandibular nerve or inferior alveolar or mental branches
• Infraorbital neuropathy (numb cheek syndrome): similar etiology
• Gradenigo's syndrome: lesions located at the petrous-temporal bone apex, causing forehead pain, ipsilateral lateral rectus palsy, and Horner's syndrome