[Spontaneous dissection of the internal carotid artery. A report of two cases]. / Disección espontánea de la arteria carótida interna. Presentación de dos casos.

INTRODUCTION: Dissection of the internal carotid artery is a condition with a broad clinical spectrum. In absence of the classical triad of cervical pain, oculosympathetic ipsilateral paralysis and ischemic cerebral symptoms a considerable index of clinical suspicion is necessary to make a diagnosis. It is therefore considered to be probably underdiagnosed. The development of new techniques for neurovascular investigation, particularly ultrasound and magnetic angioresonance have improved the possibilities of diagnosis. CLINICAL CASES: In this paper we describe two cases of dissection of the internal carotid artery representing different clinical findings in the same condition. One patient presented with unilateral paralysis of the XI, X and XII cranial nerves and the other with transient ischemic cerebral accidents. In both cases the provisional diagnosis was made in function of the duplex findings of the supra-aortic trunks and confirmed by magnetic angioresonance studies. Both patients made satisfactory progress with complete recanalization of the vessels and no recurrence of symptoms after several months of follow-up. CONCLUSION: We discuss the different clinical characteristics and findings of the neurovascular examinations.

[The validity of the classification criteria of the International Headache Society for migraine, episodic tension headache and chronic tension headache]. / Validez de los criterios de clasificación de la International Headache Society para la migraña, cefalea de tensión episódica y cefalea tensional crónica.

INTRODUCTION: We analysed the value of the diagnostic criteria of the International Headache Society (IHS) for the classification of the primary headaches in a headache clinic. PATIENTS AND METHODS: The IHS criteria were applied to classify 208 headaches in 194 patients. Forty-two had migraine, 18 tension type headache and 76 chronic daily headaches (CDH). RESULTS: The value of IHS criteria in order to distinguish migraine from tension type headache have a specificity of 94% and a predictive positive value of 99%. The predictive negative value is 63%. The more specific symptoms for migraine were severity, photophobia, phonofobia and vomits. IHS criteria for chronic tension type headache have a very low sensibility; only the 45% of these headaches meet criteria. If we applied the criteria of Silberstein et al we can see that, without the patient history, symptoms don't distinguish between chronic tension type headache, transformed migraine and new daily persistent headache. The most specific features for distinguishing the transformed migraine were worsening with activity, vomiting and pulsating. A 62% of the CDH have analgesic overuse. CONCLUSIONS: IHS criteria distinguish accurately between migraine and tension type headache. Symptoms do not differenciate the different kinds of CDH.

[Reference values for the central motor conduction time and silent period obtained by the transcranial magnetic stimulation]. / Valores de referencia para el tiempo de conducción motora central y período silente obtenidos por estimulación magnética transcraneal.

INTRODUCTION: Normal values of reference to transcranial magnetic stimulation for the motor central conduction time (CCT) and silent period (SP) is recorded in 30 healthy control subjects over abductor pollicis brevis. MATERIAL AND METHODS: We get for the CCT four measurements: two with low intensity of stimulus, 5% plus the motor threshold, with and without facilitation (CCT1 and CCT1 fac.); and two with high intensities of stimulus, elevating the magnetic stimulation intensity to 1.5 times the threshold (CCT2 and CCT2 fac.). RESULTS AND CONCLUSIONS: The mean and standard deviation of each measurement are: CCT1: 9.34 +/- 1.19, CCT1 fac.: 7.12 +/- 1.1. CCT2: 8.84 +/- 1.05 and CCT2 fac.: 6.57 +/- 1.05. Given that the CCT and SP doesn't follow a normal distribution, the medium and the 5-95% percentiles for the normal values of reference are calculated; there are: CCT1: 7.15-11.32, CCT1 fac: 5.27-9.42. CCT2: 7.05-10.73 and CCT2 fac: 4.91-9.14. For the silent period gets only one measurement employing high intensities. These last measurement were recorded in two localizations: on vertex and on motor area, selecting the greater duration. Given the great individual variability of this period in normal population absolute and ratio for the difference duration of SP between both sides are calculated. The latency of the SP is 50.2 +/- 5.99, 95 percentiles 39.1-64.63, the duration 151 +/- 32.51, 95 percentiles 102.63-239.55. The total SP measured from the discharge of the stimulus to the end of the silent period is 201.71 +/- 33.27; 95 percentiles: 151.39-296.4. The comparison of both hemispheres would give us pathological security for the 99.99% of the population for more than 14.94 ms of absolute difference, and for less of the 79.81% of ratio difference. A summary of the discoveries of the silent period in different pathologies is contributed in the discussion.