Improved white matter integrity after contralateral seventh cervical nerve transfer measured by tractographic representation

Contralateral C7 (CC7) nerve transfer surgery was shown to significantly improve the spasticity condition and the motor function of paralyzed arms. However, the involvement of the white matter tract in the recovery process is not well established. We here investigated the possible biologic explanation for this phenomenon. A 62-year-old female patient, who suffered from spastic hemiparesis due to intracranial hemorrhage, underwent CC7 transfer surgery 13 years after the initial stroke event. Six months after the surgery, the patient's Modified Ashworth Scale and Fugl-Myere score improved, even though no specific rehabilitation programs were applied. Diffusion tensor imaging (DTI) was performed before and 6 months after the surgery. The pre-surgery DTI showed both ipsilesional and contralesional CST from the cerebral peduncles to the cortices. After surgery, however, only the contralesional CST was observed. In conclusion, functional alterations of the brain white matter tract after CC7 nerve transfer surgery possibly provided a neurophysiological substrate for ameliorating the spasticity and improving the motor function in a spastic hemiplegia patient.

Mills' syndrome revisited

Mills' syndrome is an idiopathic, slowly progressive, spastic hemiparesis. We describe three cases that have been under review for a minimum of 11 years (range 11-19). In all patients, symptoms started in a leg, with a mean age of onset of 59 years (range 53-63). The only abnormality on laboratory investigations was a mildly elevated CSF protein in one case. MRI demonstrated focal T2 hyper-intensity located eccentrically in the cervical cord ipsilateral to the symptomatic side. No cerebral abnormality was demonstrated. Whilst visual and somatosensory evoked potentials were unremarkable, motor evoked potentials were abnormal in all patients: central motor conduction times were significantly prolonged unilaterally in two patients and bilaterally but asymmetrically in the third. Beta-band (15-30 Hz) intermuscular coherence, a potentially more sensitive method of assessing upper motor neuron integrity, was absent unilaterally in one patient and bilaterally in the other two. One patient developed amyotrophy and thus a picture of amyotrophic lateral sclerosis after 16 years, suggesting that Mills' syndrome is part of the motor neuron disease spectrum. Both amyotrophy and subclinical contralateral upper motor neuron disease can therefore be features of Mills' syndrome. However, even with the most sensitive electrodiagnostic techniques, unilateral upper motor neuron disease can remain the only abnormality for as long as 10 years. We conclude that whilst Mills' syndrome should be classified as a motor neuron disorder, it is a distinct nosological entity which can be distinguished from amyotrophic lateral sclerosis, upper motor neuron-dominant amyotrophic lateral sclerosis and primary lateral sclerosis. We propose diagnostic criteria for Mills' syndrome, and estimate a point prevalence of at least 1.2:1,000,000 based on our well-defined referral population in the North of England.