Role of radiology in central nervous system stimulation.

Central nervous system (CNS) stimulation is becoming increasingly prevalent. Deep brain stimulation (DBS) has been proven to be an invaluable treatment for movement disorders and is also useful in many other neurological conditions refractory to medical treatment, such as chronic pain and epilepsy. Neuroimaging plays an important role in operative planning, target localization and post-operative follow-up. The use of imaging in determining the underlying mechanisms of DBS is increasing, and the dependence on imaging is likely to expand as deep brain targeting becomes more refined. This article will address the expanding role of radiology and highlight issues, including MRI safety concerns, that radiologists may encounter when confronted with a patient with CNS stimulation equipment in situ.

Noninvasive carotid artery imaging with a focus on the vulnerable plaque.

Currently carotid imaging has 2 main focuses: assessment of luminal stenosis and classification of atherosclerotic plaque characteristics. Measurement of the degree of stenosis is the main assessment used for current treatment decision making, but an evolving idea that is now driving imaging is the concept of vulnerable plaque, which is where plaque components are identified and used to define which plaques are at high risk of causing symptoms compared with those at low risk. This review article covers the methods used for noninvasive assessment of carotid luminal stenosis and the options available for plaque imaging.

Choreathetoid movement as an unusual presentation of subdural haematoma.

Subdural haematomas can present with a wide variety of symptoms. An atypical presentation can be movement disorders. The key feature is that the history of onset is more rapid than with neurological conditions such as Parkinson's disease. The symptoms can also be an acute worsening of pre-existing disorder. The case discussed involved an 80 year old woman with bilateral choreathetoid movements attributed to a unilateral chronic subdural haematoma. The haematoma was surgically drained and the symptoms resolved. Sporadic reports of similar cases of movement disorders associated with subdural haematomas exist in the literature, but rarely do unilateral haematomas present with bilateral symptoms. Pressure effects, neurotransmitter abnormality and ischaemia have been postulated as reasons for this type of presentation. Unexplained and sudden movement disorders might warrant imaging to rule out a subdural haematoma as the cause.