Examine this patient's arms.
· Classically patient has a history of painless trauma or burns with cigarettes, hot water.
· Patient may have cuts that never seem to hurt.
· Patient may have a long history of poorly localized unpleasant pain (although pain sensation is impaired, these patients have severe pain).
· Patient may notice scoliosis during childhood.
· Wasting and weakness of the small muscles of the hands and forearm (if fasciculation is seen, then the other diagnosis that comes to mind at
this stage is motor neuron disease).
· Rarely patients may have hypertrophy in limbs, hand and feet (Lancet 1996; 347: 1593-5).
· Tone and deep tendon reflexes are diminished.
· Loss of pain and temperature sensation with intact vibration, light touch and joint position sense - this deficit is the underlying cause for any
· There may be Charcot's joints of the shoulder and elbow.
Proceed as follows:
· Examine vibration sense over the fingers, lower end of radius, elbow and clavicles (note that vibration sense is impaired only at a later stage).
· Look for Homer's syndrome.
· Examine the neck posteriorly for scar of previous surgery.
· Ask whether you may examine the following:
-The lower limbs for pyramidal signs.
-The face for loss of temperature and pain sensation (starting from the outer part of the face and progressing forward, looking for the
'onion-skin pattern' of sensory loss due to a lesion in the spinal nucleus of the fifth cranial nerve which extends from the pons
down to the upper cervical cord).
- For lower cranial nerve palsy.
- For nystagmus and ataxia (due to involvement of the medial longitudinal bundle from C5 upwards).
-For kyphoscoliosis (due to paravertebral muscle involvement).
This patient has dissociated sensory loss (lesion) due to syringomyelia (aetiology), and has had severe painless trauma or burns
How common is syringomyelia?
It is a rare disorder affecting both sexes equally; the usual age of onset is the fourth or fifth decade.
How do you explain the clinical features?
At the level of the syrinx:
· Anterior horn cell involvement causing a lower motor neuron lesion.
· Involvement of the central decussating fibres of the spinothalamic tract producing dissociated sensory loss and late
development of neuropathic arthropathy and other trophic changes.
Below the level of the syrinx:
Involvement of pyramidal corticospinal tracts resulting in spastic paraparesis (sphincter function is usually well preserved).
Involvement of cervical sympathetics:
Homer's syndrome (miosis, enophthalmos, ptosis).
What is la main succulente?
In some patients with syringomyelia the hands have an ugly appearance as a result of trophic and vasomotor disturbances; these
commonly result in cold, cyanosed and swollen fingers and palms.
What are the other causes of dissociated sensory loss?
· Anterior spinal artery occlusion (affecting the dorsal horn and lateral spinothalamic tract).
· Diabetic small-fibre polyneuropathy.
· Hereditary amyloidotic polyneuropathy.
· Leprosy (the latter three conditions affect small peripheral nerve axons).
What investigations would you perform?
MRI scan (J Neurosurg 1988; 68: 726). In the past, myelography was performed to confirm the diagnosis but was associated with
deterioration of the condition in a large number of patients.
What associated abnormalities may be present?
Amold-Chiari malformation, spina bifida, bony defects around the foramen magnum, hydrocephalus, spinal cord tumours.
What conditions may present with a similar picture?
· Intramedullary tumours of the spinal cord.
· Arachnoiditis around the foramen magnum obstructing the CSF pathway.
· Craniovertebral anomalies.
· Late sequelae of spinal cord injuries (manifest as a painful ascending myelopathy).
What is the difference between hydromyelia and syringomyelia?
Hydromyelia is the expansion of' the ependyma-lined central canal of the spinal cord, whereas syringomyelia is the formation of a
cleft-like cavity in the inner portion of the cord. Both these lesions are associated with destruction of the white and grey matter and
an accompanying reactive gliosis. In syringomyelia the process generally begins in the cervical cord, and with expansion of the
cavity the brainstem and distal cord also become affected.
What are the clinical features of syringobulbia?
· Dissociated sensory loss of the face of the 'onion-skin' pattern (extending from behind forwards, converging on the nose and
· Vertigo (common symptom).
· Wasting of the small muscles of the tongue (important physical sign).
· The process may be limited to the medullary region.
· The main cranial nerve nuclei involved are those of the fifth, seventh, ninth and tenth cranial nerves.
What does the cavity of the syrinx contain?
It contains a fluid similar to CSF but with a higher protein content.
What treatment is available? (J Neural Neurosurg Psychiatry 1981: 44: 273-84)
· Syringoperitoneal shunting (particularly in patients with basal arachnoiditis and without tonsillar descent).
· Direct drainage of the syrinx into the subarachnoid space (in post-traumatic cavitation).
· When there is an association with Arnold-Chiari malformation, the pressure is relieved by removing the lower central portion of
the occipital bone and cervical laminectomy to restore normal CSF dynamics.
What other causes of Charcot's joints do you know?
· Diabetes mellitus, especially when toes and ankles are affected.
· Tabes dorsalis, especially when knee and hip joints are affected.
What do you know about Morvan's syndrome?
The term was initially used to describe painless whitlows on the fingers but was subsequently applied to the progressive loss of pain
sensation and its effects (such
asulceration, resorption of the phalanges and loss of soft tissue) in both hands and feet (Gaaette Hebdomadaire Medicine et de
Chirurgie 1883; 35: 580). These changes are now more commonly seen in leprosy.
What do you know about the management of syringomyelia?
· Syringomyelia associated with Arnold-Chiari malformation: suboccipital craniectomy and upper cervical laminectomy to
decompress the malformation at the foramen magnum.
· Intramedullary tumour: surgery, with or without radiation therapy.
· Post-traumatic syringomyelia: surgery when the neurological deficit or pain is intolerable.
The term 'syringomyelia' (from syringx,a pipe or tube) was first used by OIlivier in 1824, in his monograph on diseases of the spinal
cord, to denote cavity formation. It denotes the presence of a large fluid-filled cavity in the grey matter of the spinal cord which is in
communication with the central canal and contains CSE
J. Arnold (1835-1915), Professor of Pathology at Heidelberg.
H. Chiari (1851-1916), an Austrian pathologist.