Distinct hyperintense MRI signal changes in the corticospinal tracts of a patient with motor neuron disease

A comprehensive review of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease affecting motor neurons with an incidence of about 1/100,000. Most ALS cases are sporadic, but 5–10% of the cases are familial ALS. Both sporadic and familial ALS (FALS) are associated with degeneration of cortical and spinal motor neurons. The etiology of ALS remains unknown. However, mutations of superoxide dismutase 1 have been known as the most common cause of FALS. In this study, we provide a comprehensive review of ALS. We cover all aspects of the disease including epidemiology, comorbidities, environmental risk factor, molecular mechanism, genetic factors, symptoms, diagnostic, treatment, and even the available supplement and management of ALS. This will provide the reader with an advantage of receiving a broad range of information about the disease.

Motor neuron disease and frontotemporal lobar degeneration: a tale of two disorders linked to TDP-43

Motor neuron disease (MND) is a neurodegenerative condition long thought to be associated only with motor weakness. Recent work now shows that cognitive difficulties are present in up to half of the patients with this disorder. About 5-10% of patients with MND have a frank dementia that resembles frontotemporal lobar degeneration (FTLD). Imaging studies show quantitative abnormalities that resemble FTLD. Moreover, biochemical studies of ubiquinated histopathologic abnormalities in MND and FTLD reveal identical inclusions of TDP-43. These findings underline a fundamental link between MND and FTLD. This paper reviews this body of work.

Amyotrophic lateral sclerosis with predominant pyramidal signs—early diagnosis by magnetic resonance imaging

OBJECTIVE

To evaluate the role of magnetic resonance imaging (MRI) in the early diagnosis of amyotrophic lateral sclerosis (ALS) with predominant upper motor neuron (UMN) signs in the initial stage of the disease.

PATIENTS AND METHOD

Two patients with ALS were found to have spastic quadriparesis with no wasting or fasciculation in the limbs in the early stage of the disease. Both were subjected to MRI of the head and cervical spine to look for any specific diagnostic feature. Both of them were followed with clinical evaluation and electroneuromyography (ENMG) for the definitive diagnosis of ALS.

RESULTS

Magnetic resonance imaging showed selective degeneration of the pyramidal tracts in the contiguous axial cuts from subcortical white matter to cerebral peduncles. The finding was more visible in the coronal section. In addition, there was T1 hyperintensity visible along the anterior aspect of the spinal cord in the cervical region. These findings were suggestive of ALS, the diagnosis that was subsequently confirmed by serial clinical follow-up and ENMG.

CONCLUSION

It is difficult to diagnose ALS in the early stage of the disease especially if the pyramidal signs predominate over the lower motor neuron (LMN) signs; MRI might be useful in such cases.

Magnetic resonance imaging reveals neuronal degeneration in the brainstem of the superoxide dismutase 1G93A G1H transgenic mouse model of amyotrophic lateral sclerosis

Magnetic resonance imaging (MRI) is becoming the preferred neuroimaging modality for the diagnosis of human amyotrophic lateral sclerosis (ALS). A useful animal model of ALS is the superoxide dismutase 1G93A G1H transgenic mouse, which shows many of the clinico-pathological features of the human condition. We have employed a 4.7-Tesla MRI instrument to determine whether a noninvasive imaging approach can reveal pathological changes in the nervous system of this animal model. Our T2-weighted MRI revealed consistent changes in brain and brainstem of these mice. Hyperintensities, indicative of neuropathology, were observed in several areas including the nucleus ambiguus, facial nucleus, trigeminal motor nucleus, rostroventrolateral reticular nucleus, lateral paragigantocellular nucleus and the substantia nigra. Histology analysis including neuronal counts of the imaged brains confirmed the T2-weighted MRI findings. Enlarged ventricles and hypointense striations, indicative of global atrophy, were also observed in the brain and cerebellum. This atrophy was confirmed by fresh brain weight data. The extensive global degeneration involving multiple structures suggests a multisystem disease that is similar to human ALS.