Syringomyelia: Causes, Symptoms, Diagnosis and Treatment

Syringomyelia is a rare neurogenic disease which can damage the spinal cord due to the formation of a fluid-filled area in the form of a cyst (Syrinx), usually found in the high cervical spine. (Also found in lumbar area but this is very rare).

The name derives from the word Syrinx, greek for a tube-formed object and the Myelum, referring to the spinal cord.

Syringomyelia

Causes

1. Syringomyelia due to blockage of CSF circulation (without fourth ventricular communication)

Representing at least 50% of all cases, this is the most common type of syringomyelia. Obstruction of CSF (cerebro-spinal fluid) circulation from the basal posterior fossa to the caudal space may cause syringomyelia of this type. The most common example is Arnold-Chiari malformation, which is also associated with communicating syringomyelia.

2. Syringomyelia with fourth ventricle communication

Approximately 10% of syringomyelia cases are of this type. The communication is visible on MRI. In some cases a blockage of CSF circulation occurs: a shunt operation may be the best therapeutic option for these patients.

3. Syringomyelia due to spinal cord injury

Fewer than 10% of syringomyelia cases are of this type. Mechanisms of injury include:

Spinal trauma
Radiation necrosis
Haemorrhage from aneurysm rupture or arteriovenous malformation or in a tumour bed
Infection (spinal abscess, human immunodeficiency virus, transverse myelitis)
Cavitation following ischaemic injury or degenerative disease

4. Idiopathic Syringomyelia

Idiopathic syringomyelia has an unknown cause and cannot be classified under any of the previous categories. Surgical decompression can help in some patients with remarkable neurologic deficit.

Syringomyelia

Clinically Relevant Anatomy

There is no exact location where the Syrinx may occur. The most common location is the upper cervical spine. Since a picture says more than a thousand words, here is a schematic representation of an upper Chiari deformation in both sagittal and intersectional view.

Epidemiology /Etiology

Syringomyelia has a prevalence of approximately 8.4 out of 100.000 individuals. This is a rough worldwide estimation. Lately, the number of patients that remain stable grow, although an older study suggested that 20% of patients suffering from Syringomyelia died at an average age of 47.

The reason for this lowering is a result of surgical interventions, better physical therapy and better treatment of complications associated with significant paresis.

The disease usually appears in the third or fourth decade of life, with a mean age of onset of 30 years.

Rarely, syringomyelia may develop in childhood or late adulthood.

Syringomyelia occurs more frequently in men than in women.

Characteristics/Clinical Presentation

The damage to the spinal cord as seen in patients suffering from Syringomyelia is caused by a Syrinx.

This is comparable to a cyst, a cavity filling with a fluid identical of similar to cerebrospinal fluid and extracellular fluid, which slowly expands, putting pressure on the spinal cord and thus damaging it.

Such a Syrinx may be a result of a spinal cord trauma, pressing spinal cord tumours, inflammation or birth-related defects (e.g. Chiari deformation or Arnold Chiari Malformation).

The symptoms identifying this particular disease aren’t always clear. There may be no symptoms at all (depending on the location of the Syrinx and the patients’ anatomical and proprioceptive properties) or there can be a number of indications such as:
Gradual muscle atrophy (especially scapular and cervical neck muscles)

Muscle function loss and muscle weakness
Decreased reflexes in the arm
Persistent headaches
Decreased sensation and sensitivity or even numbness
Radiating pain through the neck, shoulder, upper arms and upper trunk (also ventral)
Uncoordinated movements, spasms and involuntary muscle contractions
Dizziness
Nystagmus (Jerky eye movements)
Facial sensory impairment on one or both sides of the face

Sensory

Dissociated sensory loss: Syrinx interrupts the decussating spinothalamic fibers that mediate pain and temperature sensibility, resulting in loss of these sensations, while light touch, vibration, and position senses are preserved.

When the cavity enlarges to involve the posterior columns, position and vibration senses in the feet are lost; astereognosis may be noted in the hands.

Pain and temperature sensation may be impaired in either or both arms, or in a shawl-like distribution across the shoulders and upper torso anteriorly and posteriorly.

Dysesthetic pain, a common complaint in syringomyelia, usually involves the neck and shoulders, but may follow a radicular distribution in the arms or trunk. The discomfort, which is sometimes experienced early in the course of the disease, generally is deep and aching and can be severe.

Motor

Syrinx extension into the anterior horns of the spinal cord damages motor neurons (lower motor neuron) and causes diffuse muscle atrophy that begins in the hands and progresses proximally to include the forearms and shoulder girdles. Clawhand may develop.

Respiratory insufficiency, which usually is related to changes in position, may occur.

Autonomic

Impaired bowel and bladder functions usually occur as a late manifestation.

Sexual dysfunction may develop in long-standing cases.

Horner syndrome may appear, reflecting damage to the sympathetic neurons in the intermediolateral cell column.

Other symptoms

Painless ulcers of the hands are frequent.
Oedema and hyperhidrosis can occur due to interruption of central autonomic pathways.
Neurogenic arthropathies (Charcot's joints) may affect the shoulder, elbow, or wrist. Scoliosis is seen sometimes.
Acute painful enlargement of the shoulder is associated with the destruction of the head of the humerus.

Differential Diagnosis

We have to differentiate between subtypes of cystic processes in the spinal cord; not all cystic lesions can be defined as Syringomyelia.

Other similar cystic processes can be Hydromyelia, Myelomalacia, Cystic Neoplasms or Glioependymal Cysts. Syringomyelia can be easily differentiated because of its association with an underlying disorder that is characterized by obstruction of cerebrospinal fluid flow, tethering of the spinal cord, or a spinal tumour.

Syringomyelia

Diagnostic Procedures

The procedure for identifying Syringomyelia varies depending on the patients’ complaints. A neurological exam should rule out most of the symptoms we find in Syringomyelia.

Also, a well-executed anamnesis is one of the main diagnostic procedures in identifying this disease. Furthermore, we look for symptoms as we have seen in the ‘differential diagnosis’ topic.

Medical Management

There is no specific medical treatment for syringomyelia, but the origin of the disease can be met. For example, the pressure caused by the Syrinx can be relieved by surgical intervention and thus reduce pain and stop further progression of neurological symptoms. Congenital syringomyelia may require that pieces of the cervical vertebrae in the area of the cavity be removed.

Physical Therapy Management

The physical therapy for patients suffering from Syringomyelia differs depending on the location and impact of the disease unless presented with an MRI, a neurological examination should clear out at which level the syrinx occurs.

The goals of the treatment are to stop the spinal cord damage from getting worse using the techniques explained in the following paragraph and to maximize functioning. They may require active physical therapy, passive mobilizations, occupational therapy or even speech therapy.

Note: the following physical therapy techniques take into account the most frequent manifestations of this disease:

RoM
Muscle strength
Neck Stability
Balance
Coping

Occupational Therapy

We try to focus the therapy on the following subjects:

Maintaining range of motion using stretching and mobilizations of the neck and upper limb. Do note: there is no evidence to support the use of manipulations, and since the spinal cord has been damaged, most authorities advise avoiding this.

Increasing their muscle strength (Usually upper extremity and paravertebral muscles, using training schemes individualized to the patients’ tolerance)

Training neck stability (best guided by physiotherapist at first)

Sitting and standing balance can be physical and occupational therapy (referring to daily activities as in getting dressed and grooming)

Educating the patients about their disease and it’s process over time. It is important to maintain an active lifestyle but there are several risks in high impact activities which should not be overlooked. (See topic “patient advice during follow up after surgery) They should also learn about adequate pain management and coping techniques

Improving and/or maintaining communication using speech therapy (when the syrinx is present in the lower brain stem, although that should be referred to as ‘syringobulbia’)

Maximizing functional capabilities by testing and asking the patient about daily activities and then acting upon the answers.

This includes activities such as getting in and out of bed, walking, using a cane or crutches and such. Physical therapists may also refer a patient to the use of leg braces if they are deemed appropriate.

Patient advice during follow up after surgery:

Hospital Course: pain relief will be the most significant factor. Therefore it is important the patient receives a lot of bed rest and moves carefully.

During the first month after surgery: when the operation is successful, the pain and neurological symptoms should improve rapidly. The patient should try to maintain a modestly active lifestyle. It is important that these patients try to avoid tasks involving heavy lifting! Walking and performing daily activities at ease is highly recommended.

On the long term: an adequate follow-up is very important for these patients. If they do not deteriorate, they should try to maintain a relatively active lifestyle.