The Purple Book

'5 minute' Neurology

History is THE most important element of Neurological Diagnosis and review especially as the examination may often be unremarkable or non-localising.

Typical questions:

Mental Status

• Changes in memory or mood
• ability to care for oneself, ability to manage money
• difficulty with language
• geographical orientation, etc.

Skull, Spine, & Meninges

• History of head trauma, neck injury, back injury, headache or stiff neck.

Cranial Nerves

• Abnormalities in vision, hearing, smell, taste, speech or swallowing
• Facial weakness or numbness

Motor Function

• History of muscular weakness
• tremor or difficulty in initiating movements
• loss of muscle bulk, especially localised

Sensory Function

• Numbness, tingling, or altered sensation in any limbs

Coordination

• Clumsiness
• difficulty with hand writing or carrying out coordinated tasks

Gait & Station

• Abnormalities of gait
• frequent falling
• difficulty maintaining balance

General Symptoms

• History of seizures
• vertigo or loss of consciousness
• bowel or bladder difficulty.

PHx, Medication, Social

• Hereditary neurological disorder?
• many drugs affects the nervous system
• systemic illness - diabetes, HTN, alcohol & drug abuse, immunological disorders, malignancy, viral illnesses

The most important part of the Neurological exam is observation. More than half of the exam is performed by simple observation - how he/she speaks, thinks, walks, moves and simply interacts with you as examiner. Simple but careful observation will begin to localise a lesion. Formalised testing merely refines the diagnosis, and may only need a few extra steps.

Mental Status

• Cognition - essentially tested during history taking.
• Language - tested during history taking, except for naming.

Cranial Nerves

• Visual fields by confrontation – vision is processed by 1/3 of the cerebral hemispheres.
• Check pupils and eye movements – don’t forget testing saccades as well as pursuits
• Facial strength - best tested by observing the patient for asymmetries during natural speech. Observe for symmetry of eye blinks.
• Lower cranial nerves (IX-XII) - only need to be tested if dysphagia and dysarthria are present.

Motor Examination

• Adventitial movements – tics, tremor and bradykinesia are best observed during history taking
• Pronator drift – implies upper motor neuron dysfunction
• External rotation of leg – implies upper motor neuron dysfunction
• Muscle tone – important for diagnosing subtle upper motor neuron lesions and Parkinson’s disease
• Functional strength testing – more important than formal push-pull testing, more reliable, and quicker!

Sensory examination

• Focus sensory testing to the patient’s symptoms
• Sensory testing is purely subjective, so don’t over-interpret
• Check for sensory level on the back if a spinal cord lesion is suspected
• Touching nose with eyes closed – an excellent test of proprioception
• Romberg test - tests proprioception (peripheral nerves and dorsal columns), and is not a test of cerebellar function!

Coordination

• Many things cause ataxia – cerebellar lesions, sensory disorders and upper motor neuron lesions
• Don’t forget truncal stability – truncal ataxia implies a lesion of the cerebellar vermis

Reflexes

• The only purely objective part of the neurological exam
• Look for asymmetries and sustained clonus
• Don’t over-interpret the Babinski sign. Easy to elicit +ve and -ve!

Gait

• Look at the base, stride, arm-swing, turns and symmetry