RESUMEN
BACKGROUND: Traumatic subdural hygroma (TSHy) is an accumulation of cerebrospinal fluid (CSF) in the subdural space after head injury. It appears to be relatively common, but its onset time and natural history are not well defined. Considered a benign epiphenomenon of trauma, the pathogenesis of TSHy is still unclear and many questions remain unanswered. This study adds to the information on TSHy, and proposes a classification based on pathogenesis. METHODS: Thirty-four consecutive adult patients with TSHy were analyzed for clinical evolution and serial CT scan, during a period of several months. TSHy diagnosis was based on published CT scan criteria of hypodense subdural collection after trauma, without enhancement and neomembrane, with a minimum distance of 3 mm between the skull and brain. Ventricle size was analyzed by calculating the bicaudate index (BCI). For comparison, the BCI was measured from CT scan at three moments: admission, at time of TSHy diagnosis, and from last CT scan. RESULTS: There were 34 patients, aged between 16 and 85 years (mean 40), half of them were below 40 years. Road traffic crashes were the main cause of head injury. The mean time for hygroma diagnosis was 9 days. Twenty-one patients (61.8%) underwent conservative treatment for TSHy and 13 (38.2%), surgical treatment. TSHy are early lesions and can be detected in the first 24 hours after trauma, usually as small subdural effusion (SSEff). Based on clinical and CT scan findings, we divided the 34 patients into 3 groups, (Ia and Ib) without evident mass effect and (II) with evident mass effect. Group Ia includes patients without ventricle dilation; Ib, patients with associated ventricle dilations. CONCLUSIONS: SSEff detected in the first 24 hours posttrauma in our series evolved into TSHy suggesting that this is an early lesion; all THSy were divided in three groups according to the pathophysiologic mechanism. These three groups probably represent a continuum of CSF absorption impairment. Group Ia represents what most authors consider a simple hygroma, with no impairment on CSF absorption. Group Ib represent the external hydrocephalus form with various degrees of CSF imbalance, and group II were the cases presenting marked mass effect.
Asunto(s)
Efusión Subdural/clasificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Traumatismos Craneocerebrales/complicaciones , Traumatismos Craneocerebrales/diagnóstico por imagen , Traumatismos Craneocerebrales/fisiopatología , Femenino , Escala de Coma de Glasgow , Humanos , Masculino , Persona de Mediana Edad , Efusión Subdural/diagnóstico por imagen , Efusión Subdural/etiología , Efusión Subdural/fisiopatología , Tomografía Computarizada por Rayos XRESUMEN
During the past two years we studied six infants with subdural collections of fluid. All patients had macrocrania and excessive transillumination of the head. Rapid head growth was common but five patients were otherwise asymptomatic. Subdural taps performed on five children confirmed the presence of abnormal fluid over the cerebral convexities. Subdural fluid in four patients was compatible with effusion and in another with a hematoma. Computerized tomographic evaluation of all infants showed ventricular enlargement, wide cerebral sulci, decreased density in the anterior temporal regions, large sylvian cisterns, prominent interhemispheric fissures, and decreased density over the cerebral convexities. The CT findings resembled cerebral atrophy but psychomotor development and neurologic examinations have been norma.