Makindo Medical Notes.com

Related Subjects: |Neurological History taking |Cortical functions |Motor System |Sensory System |Mental state Examination |Speech and Language Exam |Cranial nerves and examination |Assessing Cognition

It is so important to take a detailed history and a timeline of problems as they have arisen. Neurological diagnosis is 90% historical supplemented with signs and imaging and other tests.

Location, causation, confirmation, explanation, treatment

• Location: where is the lesion? use the history, clinical signs and knowledge of functional neuroanatomy
• Causation: What is the lesion? the speed of onset, resolution, periodicity helps, age of person, risk factor presence of absence
• Confirmation: The wise use of imaging, neurophysiology, genetics to support the diagnosis
• Explanation: Sharing information with patient and involvement in the ongoing management
• Treatment: Treatable, Untreatable as no treatment known or for example surgery too dangerous.

Symptoms and sign timings and periodicity

• Seconds and minutes: Vascular e.g. SAH, TIA, Stroke (Negative neurology), Electrical? seizure (Positive neurology)
• Hours to Days: Inflammation e.g. demyelinating plaque with MS, ADEM, transverse myelitis, Infection e.g. Viral Encephalitis, Meningitis
• Weeks to Months: Degenerative e.g. Motor neuron disease, Malignant neoplasm? Aggressive primary brain tumour or Metastatic disease, Creutzfeldt Jacob disease
• Subacute combined degeneration
• Months to Years: Alzheimer's disease, Parkinson's disease and other degenerative diseases
• Slow growing Primary brain tumour e.g. meningioma

The duration of symptoms and periodicity helps too

• Resolution to normal within minutes with later recurrences: Epilepsy, TIA
• Worst at onset and then slowly improves with time over days/weeks: Stroke, Multiple sclerosis, Inflammatory
• Diurnal - Myasthenia gravis weakness worsens with day, Headache of space-occupying lesion gets better to recur on waking next morning
• Episodes lasting days followed by resolution and then further episodes, Remitting relapsing MS

Levels of damage and findings

Cortical level

• Psychological/Functional/Malingerers: Various illnesses with physical representations of psychiatric disease. Poorly understood. Functional patients are genuine and need help to overcome their 'block' and need empathy and help. Malingerers are deliberately faking symptoms and signs.
• Cortex - the right cortex manages the left side of your world and vice versa. A right cortical lesion may cause contralateral face, arm, leg and trunk weakness, hemisensory loss and hemianopia and cortical signs such as dysphasia, alexia, acalculia (dominant), apraxias (non-dominant)
• Internal capsule ? As cortical but no ?cortical signs?

Subcortical

• Subcortical lesion and Basal ganglia? movement disorders? chorea and parkinsonism, hemiballismus, dementia
• Thalamus Several nuclei mostly sensory, Impaired complex sensory functions, Thalamic pain, memory loss

Brainstem

• Brainstem lesions can cause contralateral hemiparesis and hemisensory loss associated with ipsilateral cranial nerve palsies.
• Midbrain ? III, IV, Red nucleus, Medial lemniscus, substantia nigra, corticospinal tracts, Reticular activating system
• Pons ? V, VI, VII, VIII, Cerebellar connections
• Medulla IX, X, XI, XII (Corticospinal fibres decussate here)

Cerebellar lesions

• Lateral Lesions cause ipsilateral cerebellar signs.
• Midline lesions cause truncal ataxia, lateral lesions affect limb coordination.

Spinal cord (starts at foramen magnum and ends at L1/2)

• lesion above C5-T1 quadriplegia as output to arms and legs lost
• Below T1 weakness paraplegia as output to legs lost with preservation of arms.
• Lesions may be partial and selective ?dissociative? e.g. loss of vibration but the preservation of pain depending on the tract involved.

Cauda equina

• LMN roots from the cord within the spinal canal.
• Damage here causes pain, sensory loss and weakness in the area of the roots affected.
• Usually both legs are weak and reflexes absent
• Loss of anal tone and reduced anal reflex.

Anterior horn cell

• LMN weakness, wasting, fasciculations, loss of reflex e.g. MND

Peripheral nervous system

• Nerve roots: dermatomal and localised pain, LMN weakness, loss of reflex
• Peripheral nerves: generalised glove and stocking sensory loss, motor loss, autonomic loss
• Individual nerves can be affected in patterns that are usually straightforward with both sensory and motor components
• Motor end plates disease e.g. MG or LEMS weakness which is fatigable. Ptosis, diplopia.
• Muscle disorder? muscle weakness with exercise, muscle wasting or pseudohypertrophy. General and respiratory muscle weakness