Role of MRI in the diagnosis of Mills syndrome

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.

Chronic spastic atrophic hemiparesis with benign course

We present the clinical and neuroimaging data of 4 patients (mean age: 62 years, range 54-67; mean follow-up: 19.5 years, range: 26 months-29 years) with chronic spastic atrophic hemiparesis (CSAH). Neuroimaging findings were non specific, CT scan and MRI showing white matter lesions located within the centrum semiovale in two cases, parieto-occipital lobe and pons in one case each. This study underlines that patients with CSAH may have a good long-term prognosis. MRI studies may demonstrate associated lesions within the white matter or brainstem and are advisable in all subjects with CSAH, but further studies are necessary to clarify the nature of the observed lesions.

Giant congenital nevus and chronic progressive ascending hemiparesis (Mills syndrome). Report of a case

We describe the case of a 20 year old boy with a giant congenital nevus who developed a chronic progressive ascending hemiparesis. The association of the pigmented lesion with a focal neurological deficit is pathognomonic for neurocutaneous melanosis complicated by a leptomeningeal melanoma. MR imaging at 1.5 tesla ruled out such a possibility and showed a small aspecific pontine lesion along the route of the corticospinal tract. We discuss possible etiologies.