[Sciatalgy: which imaging in first intention?]. / Sciatalgie: quelle imagerie en première intention?

Lombosciatalgy is a very common pathology and accounts for one of the most important problems of the public health. Usually it is a symptom that decreases with medical treatment. MRI or CT examinations may be asked for when symptoms persist for more than 7 weeks after medical treatment, symptoms increase or if there is a manipulation or infiltration foreseen. When there is a doubt on the specific origin of the symptoms, in other words when the pathology is secondary to an inflammatory/infectious, traumatic or tumoral aetiology, X-rays are performed followed by a complementary examination by CT or MRI. A CT-scan will be performed mainly in the workup of pathology of the intervertebral disk, or in a posttraumatic setting. An MRI is advisable when there is a suspicion of a primary or secondary tumour, infection or inflammation and in stenosis of the spinal canal.

Bilateral lesions of the globus pallidus in a young woman.

We report a case of stroke due to cocaine abuse in a 30-year-old woman. The initial examinations pointing to this diagnosis were CT and MRI. Magnetic Resonance Imaging revealed bilateral globus pallidus infarction characterized by restricted Diffusion with low ADC values. There was also a partial hemorrhagic component confirmed on T2* sequence. After gadolinium injection there was a ring enhancement consistent with a blood brain barrier leakage. Similar lesions have been described in post hypoxic-anoxic injuries such as following cardiac arrest, severe blood loss and CO intoxication.

Recurrent status epilepticus associated with Hashimoto's encephalopathy.

Hashimoto's encephalopathy (HE) is an infrequent disease with no well-known physiopathology. Status epilepticus is rarely reported in association with HE. We describe the 7-year evolution of a young woman who presented with recurrent status epilepticus as the main complication of HE. This evolution was especially marked by the occurrence of steroid-refractory symptoms and a poor outcome with persistent cognitive and behavioral consequences. We point out that the frontal lobes are especially implicated in these symptoms. This patient highlights the risk of multiple relapses and the need for a long follow-up period. We describe her clinical and paraclinical features, compare this patient to similar case reports, and comment on her outcome.

Is haemosiderin visible indefinitely on gradient-echo MRI following traumatic intracerebral haemorrhage?

Gradient-echo (GE) MRI has been demonstrated to be the most sensitive current technique for detection of intracerebral haemosiderin, especially in the chronic stage of haemorrhage. Our purpose was to see whether GE MRI shows old haemorrhage indefinitely. We reviewed serial GE images of 105 adults with imaging features consistent with post-traumatic intracerebral haemorrhage, who had serial MRI at 1, 4-6, 12, and 24 months after trauma. Of 1235 scattered low-signal foci consistent with isolated intracerebral haemosiderin deposits on images at 4-6 months, 248 (20.1%) were not seen at 24-month assessment. Reviewing individual patients, we saw that in 71.8% of those with scattered haemosiderin deposits and 46.4% of those with haemosiderin surrounded by gliosis, the low-signal foci appeared less conspicuous with time. Even given certain limitations to the interpretation of these findings, it would appear that, even with the use of GE MRI, time affects the visibility of haemorrhagic intracerebral lesions. We therefore conclude that a time of 4-6 months to 1 year or slightly more should be recommended for most precise detection of haemosiderin deposits on MRI of head-injured patients, should this be thought desirable. Normal GE images may not exclude old haemorrhage.