Clinico-morphological correlation in syringomyelia: a statistical study assisted by computer measurement of magnetic resonance images

Cell Therapy as a New Approach to the Treatment of Posttraumatic Syringomyelia

BACKGROUND

Cell transplantation with autologous bone marrow-derived mesenchymal stromal cells (MSCs) seems to be a therapeutic promise for patients with established spinal cord injury, achieving improvement in their quality of life, but there is no experience with the application of this type of cell therapy in patients suffering posttraumatic syringomyelia.

OBJECTIVE

To study the possible utility of cell therapy with autologous MSCs in posttraumatic syringomyelia.

METHODS

A 40-year-old man with complete paraplegia since 1991 as a consequence of a Th4 vertebral fracture showed a great posttraumatic syringomyelia that extended up to C2 vertebral level, without signs of recent worsening. Autologous MSCs (150 × 10⁶) were injected into the syrinx, without drainage or aspiration.

RESULTS

One year after cell therapy, syrinx was reduced without collapse of cervical spinal cord. During the course of follow-up, clear clinical improvement was observed, mainly in sphincter dysfunction.

CONCLUSIONS

Injection of MSCs in the syrinx of posttraumatic syringomyelia is safe and is associated with clinical and neuroimaging improvement. The possibility of cell therapy as a new approach to posttraumatic syringomyelia, or even for idiopathic syringomyelia, is an open door that requires further study.

Effects of surgery on the sensory deficits of syringomyelia and predictors of outcome: a long term prospective study

OBJECTIVE

To quantify the effects of surgery on the thermal deficits of syringomyelia and assess the predictors for such effects.

METHODS

The subjects were 16 consecutive patients (12 men, 4 women; mean (SD) duration of sensory symptoms, 5.1 (4.5) years) presenting with the typical symptoms of syringomyelia related to Chiari I malformation or trauma, and requiring surgical treatment. They were evaluated before surgery, then at six months and two years. Sensory evaluation included determination of the extent of thermal deficits and quantitative assessment of thermal, mechanical, vibration detection, and pain thresholds. Neuropathic pain intensity was evaluated on visual analogue scales. Magnetic resonance imaging was done before and after surgery to measure syrinx dimensions.

RESULTS

The magnitude and extent of thermal deficits improved in a subgroup of patients and this was best predicted by the duration of sensory symptoms: patients operated on less than two years after the onset of their symptoms tended to improve, while those operated on later were stabilised or deteriorated slightly. The effect of surgery on thermal deficits was correlated with the duration of sensory symptoms. Surgery also affected vibration deficits in patients with the Chiari malformation, neuropathic pain on effort, and syrinx dimensions.

CONCLUSIONS

The duration of sensory deficits is the best predictive factor of the efficacy of surgery for the thermal symptoms of syringomyelia. Early surgery is required if these deficits are to be minimised.

An electromechanical testing device for assessment of hand motor function

Instrumentation was designed and constructed to assess the strength and function of the intrinsic muscles of the index and long fingers of the hand. The device consisted of two beams instrumented with strain gages, signal conditioners, and a microprocessor-based embedded controller. A study conducted on four weak spinal cord injury (SCI), three nonweak SCI, and 21 control subjects demonstrated a trend of reduced maximum pinching force between the index and long fingers in weak SCI subjects compared with the other two groups. Weak SCI subjects also demonstrated a significantly slower rapid alternating movement speed of the index finger compared with the other two groups. The instrument has potential use as a clinical tool for quantitative evaluation of the progression of hand motor dysfunction.

[Correlations between clinical deficits, motor and sensory evoked potentials and radiologic aspects of MRI in malformative syringomyelia. 27 Cases]

Twenty-seven patients (15 males, 12 females, age range: 16-66 years) were admitted for malformative syringomyelia diagnosed on MRI with measures of syrinx extending and transverse diameter. Posterior tibial somatosensory evoked potentials (PT SEP), median (M SEP), trigeminal (V3 SEP), brain stem auditory evoked potentials (BEAP), cortical and cervical motor evoked potentials (MEP) were correlated with clinical and radiological findings. SEP abnormalities were not correlated with the duration of symptoms. PT SEP proved to be more sensitive than M SEP. MEP abnormalities were very frequent (87% of the cases), even without clinical motor deficits. Trigeminal SEP were more sensitive than BEAP which were not related to the presence of associated cranio-vertebral abnormalities. We found no significative relationship between clinical and radiological results. Moreover, there was a positive relationship between electrophysiological and radiological results: abnormal trigeminal SEP were detected in 85% of the patients with high cervical syringomyelia. In all cases, trigeminal SEP and MEP should be done in association with M and PT SEP as both of them detect subclinical evidence of spinal cord dysfunction in syringomyelia.

Posttraumatic syringomyelia: profound neuronal loss, yet preserved function

Posttraumatic syrinxes may extend many cord segments rostral to a spinal cord injury (SCI) and significantly dilate the spinal cord, yet few neurologic deficits may be noted. Careful physical examination may reveal ascending loss of pain and temperature without evident functional motor decline. We present a 49-year-old man with T4 paraplegia and a large posttraumatic syrinx who died 3 weeks after syringoperitoneal shunting. Neuropathologic study revealed a large bilateral syrinx cavity from T1 to C6 that tapered to a small unilateral syrinx at C2. Light microscopy of sections from T1 to C2 showed massive loss of intermediate to intermedio-lateral gray neurons and moderate reduction of motoneurons at T1 to C6 levels. Despite these findings, manual muscle testing results remained normal for wrist extensors and elbow extensors, and the patient continued to perform independent sliding board transfers. We conclude that this large progressive syrinx did not merely dissect neural elements apart but caused extensive neuronal damage. Loss of interneurons was evident in spinal segments with preserved strength and function. Possible mechanisms to explain the relatively minimal clinical deficits in view of the neuronal loss are discussed.

Utility of early postoperative MRI in hindbrain-related syringomyelia. A preliminary prospective study on five patients

We report a series of five patients operated on for hindbrain-related syringomyelia with posterior fossa decompression and duraplasty. In all cases an early postoperative MRI was performed (24-36 h after surgery). These images have been compared with the preoperative ones and with those obtained, 1, 3 and 6 months after operation. Both before and after surgery there was not always a tight correlation between clinical and MRI pictures. In all but one patient the early postoperative MR images showed a reduction of syrinx size and were as to those obtained later. We discuss the results observed in our small series and analyze the role of early postoperative MRI studies in patients with hindbrain-related syringomyelia.