Usefulness of high b-value diffusion-weighted MRI in the diagnosis of Creutzfeldt-Jakob disease.

BACKGROUND: current diagnostic criteria of probable Creutzfeldt-Jakob disease (CJD) include a combination of clinical, EEG and analytic data. Recent data indicate that brain MRI including fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI) sequences can be a valid and reliable tool for the diagnosis of CJD. We describe our experience with high b-value (3000s/mm(2)) diffusion-weighted imaging (DWI) in patients with probable or definite CJD and compare it with standard b-value (1000s/mm(2)) DWI. METHODS: we performed a retrospective analysis of patients admitted to our Hospital Service between 2002 and 2008 with a final diagnosis of probable or definite CJD. Patients were examined using either a 1.5 Tesla or a 3 Tesla MRI. The MRI protocol included T1-weigthed spin-echo sequences, T2-weighted fast spin-echo, FLAIR and DWI sequences with high b-value and standard b-value. RESULTS: during the study period there were 7 patients with probable or definite CJD. Only 3 patients (43%) showed changes on FLAIR sequence consistent with CJD. All the cases were detected with high b-value DWI, including 2 cases (28%) that would have been missed using standard b-value (1000s/mm(2)) DWI. In all the patients the changes were more conspicuous and extensive at high b-value DWI (b=3000s/mm(2)). CONCLUSION: our data indicate that high b-value DWI may improve the sensitivity of brain MRI for the diagnosis of CJD, allowing the detection of some cases that would have been overlooked by conventional sequences.

[Acute phenytoin poisoning secondary to an interaction with ticlopidine]. / Intoxicación aguda por fenitoína secundaria a interacción con ticlopidina.

INTRODUCTION: Ticlopidine and phenytoin are two drugs which are widely used in everyday clinical practice, the first as a platelet anti-aggregant and the second as an anti-epileptic agent. Their association is not uncommon, since there is a high incidence of epileptic crises of vascular origin in adults. CLINICAL CASE: We present the case of a 77 year old man who had been treated for twenty years with phenytoin for partial crises secondary to a left frontal hematoma. He then followed treatment with ticlopidine for a femoropopliteal bypass, and the dose was later increased because of a vertebro-basilar ictus. On both occasions he presented with ataxia, dysarthria and nausea due to phenytoin intoxication. The blood levels of this drug were above the therapeutic level. The symptoms disappeared and the patient returned to normal after reduction of the dose of phenytoin and suspending treatment with ticlopidine. DISCUSSION: The mechanism of action of ticlopidine at cytochrome P450 level, inhibiting the metabolic clearance of phenytoin, was responsible for this interaction. We have found only three other cases of interaction between these drugs in the literature, and ours is the first to be published in Spain. CONCLUSION: We emphasize the importance of checking plasma phenytoin levels when starting treatment with ticlopidine, since it may be necessary to reduce the dose of phenytoin.

[The headache in general neruological practice]. / La cefalea en la consulta de neurología general.

INTRODUCTION: Headache is one of the most frequent causes of consultation in a neurology clinic. We present a descriptive, epidemiological study about such a pathology in a general neurology clinic. We evaluated as the most relevant points the frequency of different types of headaches, the reasons for remission and diagnosis concordance with the remitting doctor, normally the General Practitioner. PATIENTS AND METHODS: The collection of data was carried out by means of structured interviews over a three month period. Apart from the epidemiological data of the subjects, the characteristics of the headache, the medication and its possible overuse, were also collected. A systematic neurological examination of all patients was carried out. RESULTS: 286 patients were included. The frequency of different diagnosis (the most frequent chronic daily headache, 39.2%), the number of patients who abused of analgesics (31.8%) and the diagnosis concordance with the referring doctor (20%) was analyzed among other variables. CONCLUSIONS: The study highlights the high number of patients suffering from daily chronic headache and the fundamental role that the abuse of analgesics plays in this diagnostic entity. The diagnosis concordance is too low. A correct initial diagnosis as a result of a better neurological training in primary care would prevent in greater numbers the abuse of analgesics and would offer a better quality of care.

[Palpebral ptosis and blepharospasm secondary to hemispheric cerebral infarction]. / Ptosis palpebral y blefarospasmo secundarios a infarto hemisférico cerebral.

A case that combines cerebral eyelid ptosis and blepharospasm secondary to cerebral hemisphere infarction is shown. EMG recording from the facial and eyelid muscles revealed lack of the levator palpebrae superioris, orbicularis oculi and corrugator muscles activity. Any voluntary opening attempt lead to a simultaneous contraction of the three muscles. Blink reflex responses were normal although showed facilitation features on the right side and mild inhibition characteristics from the left side. Median nerve SEP revealed a loss of precentral components (P22-N30) as well as a delay and amplitude decrease of N20. Transcranial magnetic stimulation disclosed a complete lesion of corticospinal pathway for right upper limb. In this case, a right hemisphere lesion caused an unusual eyelid motor abnormality: cerebral eyelid ptosis and blepharospasm induced by the voluntary eyelid opening.