Coordination, sensory and peripheral system Dr. Waleed Dabbas Introductory course

Definition Performing complex movements smoothly and efficiently depending on intact sensory and motor functions as well as intact cerebellum. Afferent and efferent pathways convey the information to and from the motor cortex,basal ganglia,thalamus,vestibular and brain stem and the spinal cord. Doing proper fine movement at proper time in a proper time

Testing the cerebellar function Stance and gait(truncal ataxia) Speech(dysarthria). Eye movement (nystagmus) Limb coordination.

Limb coordination Finger to nose test: Ask the patient to touch their nose with the tip of their index finger and then touch your fingertip. Make it more sensitive by changing the position of your target finger.

Rapid alternating movements: Ask the patient to tap a steady rhythm rapidly with one hand on the other hand or table. Abnormality include slow irregular rhythm (Dydiadochokinesis) Heel to shin test: With patient lying supine ask him to lift the heel into the air and place it on their opposite knee,then slide their heel up and down their shin between knee and ankle.

Apraxia or dyspraxia Difficulty or inability to perform a task despite normal sensory and motor function. Sign of high cortical dysfunction (non dominant frontal or parietal lobes). Examination done by asking the patient to perform imaginary act(drinking cup of tea), copying a movement you make or a geometric figure like interlocking pentagons. Gait apraxia, dressing apraxia, constructional apraxia

Sensory system Spinothalamic tracts: Sensation Includes light touch, pain, temperature and vibration. Most of pain and temperature fibers cross to the contralateral spinothalamic tracts within one or two segments of entry to the spinal cord. Dorsal column: proprioception by testing the joint position. The fibers remains ipsilateral up to medulla. High cortical sensations which includes two point discrimination, stereognosis (tactile recognition), graphaesthesia (identification of letters or numbers traced on skin)

Presenting symptoms of sensory system diseases Parasthesia:tingling Dysaethesia:unpleasant paresthesia Hypoaesthesia: reduce sensation to normal stimulus Analgesia: numbness or loss of sensation Hyperaesthesia:increase sensitivity to stimulus Allodynia: painful sensation from non painful stimulus Hyperalgesia: increased sensitivity to painful stimulus

examination Light touch stereognosis and graphaesthesia Superficial pain Temperature Vibration Joint position

Peripheral neuropathy(axonal neuropathy) Affect lower limbs starting from toes (length dependent). Upper limbs involve when the symptoms reach the knee (stocking and glove).

Peripheral nerves mononeuropathy Median nerve Carpal tunnel syndrome median nerve compressed as it passes the flexor retinaculum and the carpal bones at wrist. The most common entrapment neuropathy. Sensory symptoms include pain in the hands and extends from the thumb,index and middle fingers to the arm occasionaly. Motor uncommon weaknes of abductor pollicis brevis and opnens pollicis. Tests: tinel test,phalen test.

Radial nerve Compressed as it runs through the axilla,in the spiral groove. Cause wrist drop Examination: weakness of brachioradialis(elbow flexion),extensors of the arm(triceps),wrist and fingers. Sensory:dorsum of the hand.

Ulnar nerve Affected at elbow Examination: palpating the nerve in ulnar groove. Look for wasting of interossei,adduction of fingers. Sensory:ulnar side of the hand

Common peroneal nerve Commonly injured at the head of fibula Examination: causing weakness of foot dorsiflexion and eversion,weakness of big toe extension (extensor hallucis longus) Intact ankle reflex Sensory: dorsum of the foot.

Lateral cutaneous nerve of the thigh Purely sensory nerve. Compressed or injured under the inguinal ligament producing paresthesia in the lateral side of thigh(meralgia parasthetica)

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