Investigation of Neurological Disorders

šŸ§  Diagnosis

  • Diagnosis: Process of identifying a possible disease/disorder.

  • Disease: An abnormal condition negatively affecting structure/function of part/all of an organism.

  • Typically associated with specific symptoms and signs.

šŸ©ŗ The Clinical Method in Neurology

Steps:

  1. Elicitation of clinical facts:

    • Via patient history

    • Neurological examination

  2. Interpretation of symptoms/signs in physiological and anatomical context

  3. Syndromic formulation + localization of lesion = Anatomic diagnosis

  4. Anatomic diagnosis + onset/course + other signs + lab tests = Pathologic/Etiologic diagnosis

Purpose:

  • Enables proper treatment

  • Assists in prognosis

  • Allows for genetic counselling (hereditary diseases)

  • Essential for scientific study of diseases

šŸ§Ŗ Investigation Methods

1. Laboratory Tests

  • Blood tests:

    • Blood sugar

    • Liver function

    • Kidney function

    • RBC, WBC, Platelets

    • Alcohol, Drugs

  • Indications:

    • Encephalopathy (hypoglycemia, hepatic, renal failure)

    • Intoxication

2. Cerebrospinal Fluid (CSF) Examination

  • Indications:

    • Infections (meningitis, encephalitis)

    • Tumors

    • Multiple sclerosis (MS)

šŸ–¼ Neuroimaging

General:

  • Purpose:

    • Visualize internal structures

    • Aid diagnosis/treatment

    • Compare to database of normal anatomy

A. X-ray

  • Technique:

    • Radiograph using X-ray detector and pulse

    • Bones (calcium-rich) absorb X-rays ā†’ visible shadows

  • Used for:

    • Skull

    • Spine

    • Myelography

  • Indications:

    • Fractures, trauma

    • Disc herniation

B. Ultrasound (US)

  • Purpose:

    • Visualize soft tissues, vessels, and blood flow

  • Indications:

    • Carotid/vertebral artery evaluation (stenosis, occlusion)

    • Transcranial Doppler for intracranial arteries

C. CT Scan (Computed Tomography)

  • Uses X-rays from multiple angles

  • Output: Cross-sectional images of the brain

  • Indications:

    • Stroke (ischemic/hemorrhagic)

    • Trauma (bleeding, concussion, subdural hematoma, fractures)

    • Tumors (malignant, benign)

D. MRI (Magnetic Resonance Imaging)

  • High-quality 2D/3D brain images using magnetic fields

  • fMRI: Measures blood flow changes during activity

  • Planes: Axial (horizontal), Sagittal, Coronal (frontal)

  • Indications:

    • Tumor

    • MS

    • Atrophy

    • Hydrocephalus

    • Detailed white/grey matter imaging

    • Spinal cord

fMRI Clinical Uses:

  • Functional mapping (e.g., language areas)

  • Seizure analysis

  • Stroke recovery

  • Alzheimerā€™s detection

  • Psychiatric disorders (e.g., depression)

  • Surgical planning

fMRI Criticism:

  • Low power, small samples

  • Reliable in general trends, but not individuals

E. PET (Positron Emission Tomography)

  • Nuclear medicine technique

  • Tracks metabolism in the brain

  • Indications:

    • Tumors

    • Degenerative diseases (Alzheimerā€™s, Parkinsonā€™s)

āš” Electrophysiology

A. EEG (Electroencephalography)

  • Monitors brain's electrical activity via scalp electrodes

  • Non-invasive

  • Uses:

    • Epilepsy

    • Encephalopathy

    • Brain death

    • Sleep disorders

    • Coma

B. Evoked Potentials

  • Electrical responses after stimuli

  • Types:

    • VEP: Visual

    • BAEP: Brainstem auditory

    • SSEP: Somatosensory

  • Uses:

    • MS

    • Myelopathy

C. EMG-ENG

  • Electromyography & Nerve Conduction Studies

  • Tests nerve and muscle function

  • Uses:

    • Neuropathies, polyneuropathies

    • Muscle diseases

šŸ§  Neuropsychological Testing

  • Studies link between brain function, cognition, and behavior

  • Assesses damage effects from injury/illness

Tests Cover:

  • Intelligence

  • Memory

  • Language

  • Executive function

  • Visuospatial abilities

  • Dementia-specific

  • Mood disorders

  • Computerized tests

Executive Function Tests:

  • BADS

  • CNS Vital Signs

  • CPT

  • COWAT

  • d2 Test of Attention

  • D-KEFS

  • Digit Vigilance Test

  • Rey-Osterrieth Complex Figure

  • Ruff Figural Fluency Test

  • Stroop Test

  • WCST

  • Trail Making Test

  • Symbol Digit Modalities Test

  • Test of Everyday Attention (TEA)

  • Tower of London Test

  • PASAT, etc.

šŸ“„ Case Reports

Case 1: Male, 60 y/o

  • Complaint: Headache

  • Details:

    • Duration: 4+ weeks

    • Blunt, diffuse, worse in morning, increasing

    • No relief with rest or analgesics

    • Associated: diplopia, hand incoordination, nausea

  • Neuro Exam:

    • Right facial palsy

    • Right limb weakness

    • Right sensory loss

    • Mild speech problem

  • Diagnosis: Brain tumor

  • Localization: Left hemisphere

  • Tests: CT/MRI

  • Treatment: Neurosurgery

Case 2: Female, 20 y/o

  • Complaint: Loss of consciousness

  • Details:

    • First episode

    • Strange sensations, sleep deprivation

    • Involuntary limb movement, tongue biting

  • Diagnosis: Epilepsy

  • Tests: EEG, CT/MRI

  • Treatment: Antiepileptic medication

Case 3: Male, 60 y/o

  • Complaint: Fever, headache, light/sound sensitivity, psychomotor slowing

  • Neuro Exam:

    • Neck rigidity

    • High fever

    • Drowsiness

  • Tests: Lumbar puncture (CSF analysis)

  • Diagnosis: Meningitis (presumed)

  • Treatment: Antibiotics

āœ… Summary

  • Diagnosis uses multiple tools:

    • History

    • Physical and neurological examination

    • Imaging

    • Electrophysiological studies

    • Neuropsychological testing

  • Proper diagnosis ā†’ Effective treatment and recovery