Sirs: Reversible posterior leukoencephalopathy syndrome (RPLS) during acute hypertension, with oedema in predominantly posterior cerebral areas, is a well-known clinical and radiological event. To date however, no reports have referred to involvement of the spinal cord. We describe a patient with RPLS in association with extensive reversible oedema of the cervical cord. A 44-year-old woman, whose blood pressure (BP) had not been checked for several years, was admitted to our department following a 15-day period of weakness in her lower limbs with progressive difficulty in walking, constipation and urinary urgency, together with headaches, drowsiness and blurred vision. She used oral contraceptives, had two spontaneous miscarriages, and was a heavy smoker. The patient was negative for substance abuse. Neurological examination revealed moderate paraparesis, brisk tendon reflexes, bilateral Hoffmann and plantar extensor response. The patient was slightly disoriented and had severe headaches. Her BP was 240/140 mmHg. Blood tests and CSF examination were normal. Examination of the fundus oculi disclosed hypertensive retinopathy. Brain MRI revealed abnormal high signal intensity localized in the brainstem in fluid-attenuated inversion recovery (FLAIR) sequences, while spinal T2weighted sequences showed extensive hyperintense areas from the craniocervical junction to the 7th vertebra, without contrast enhancement (Fig. 1A, B). Treatment with anti-hypertensive drugs was commenced. Within two weeks, BP had returned to normal and stabilised, and conventional MRI displayed a complete resolution of abnormalities in the cervical cord and nearly complete resolution in the brainstem (Fig. 1C, D). Diffusion-weighted imaging (DWI) was normal. Following consistent improvement of paraparesis, which completely disappeared one month later, the patient was subsequently discharged. At the six-month follow-up, the subject was completely asymptomatic, neurological and MRI findings were normal, and BP had stabilised at normal values following chronic antihypertensive treatment. RPLS, with oedema in the posterior cerebral lobes and brainstem, is a relatively common occurrence in acute hypertensive episodes [1, 2]. In addition to hypertension, RPLS may be related to an endothelial dysfunction induced by underlying conditions including eclampsia, renal failure, cocaine use and immunosuppressive drug therapy. On rare occasions, predominant involvement of the brainstem with relative sparing of the posterior lobes may occur [3]. The pathogenesis of HTE seems to be related to autoregulatory failure resulting in passive overdistension of cerebral arterioles, rather than to vascular spasms as previously assumed. When a sudden, sustained upsurge in BP overwhelms the upper limit of cerebral blood flow autoregulation, it causes segmental vasodilatation, disruption of the blood-brain barrier and extravasation of fluid into the interstitium [4, 5]. The reversibility of lesions observed at MRI follow-up, performed once BP had returned to normal, strongly supports this theory [6], confirming how lesions reflect vasogenic rather than cytotoxic oedema. Ischemic lesions are uncommon in RPLS; indeed, vasogenic oedema are likely capable of irreversibly altering tissue perfusion, causing infarction in surrounding regions, only in very severe cases not receiving prompt treatment. Although studies performed to investigate spinal cord blood-flow regulatory mechanisms are scarce, important experimental results have confirmed the presence of autoregulatory mechanisms throughout the central nervous system [7], thus establishing a clear concordance between vascular dynamics in the brain and spinal cord. Accordingly, as occurs in cerebral blood flow, hypertensive episodes may be capable of altering autoregulation of spinal blood flow. On exceeding the upper limit of autoregulation, reversible vasogenic oedema may also occur in the spinal cord. Moreover, in HTE, the extremely rare observation in the cord of reversible oedema, commonly reported in the brain, suggests a higher sensitivity of the LETTER TO THE EDITORS
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Jun 18, 2024
T Arslan + 1
Open Access