A neglected case of headache.

Sir,

Thrombosis of dural sinuses and cerebral veins is an infrequent but potentially fatal disease and may cause serious consequences in survivors. This uncommon form of stroke usually affects young individuals and represents 0.50-1% of all strokes.[1] Diagnosis is often missed because of the heterogeneity in clinical presentation and etiological factors. We report a rare case of superior sagittal sinus thrombosis who was incidentally diagnosed to have diabetes mellitus.

A 35-year-old male from a rural background presented with a history of gradually worsening diffuse headache of four weeks’ duration which used to become worse with any kind of movement and exposure to light. He had a history of anorexia, low-grade fever which was never documented and generalized weakness for two weeks. There was no history of otitis media or mastoididtis. His past history and family history were negative for any significant chronic illness, coagulopathy or head trauma. He was taking analgesics, escitalopram and clonazepam at the time of presentation. There was no history of addiction. In view of headache, fever, anorexia, and generalized weakness, he was diagnosed to have tuberculosis by a primary care physician from where he was referred to us. On examination he was conscious, oriented, co-operative, obese with normal vitals. Abdomen, cardiovascular system and respiratory system were normal with no focal neurological deficit. Fundus examination showed evidence of bilateral papilledema. Hematological, coagulation and biochemical parameters were within normal limits except random plasma glucose was 386 mg/dl, glycosylated hemoglobin was 8.6%. Other laboratory work up for autoimmune disorders including anticardiolipin antibody, antinuclear antibody (ANA), C reactive protein (CRP), complement levels and pathergy test which were within normal limits. Subsequently, he was subjected to brain imaging. Unenhanced computerized tomography (CT) showed a triangle sign [Figure 1] whereas contrast-enhanced CT revealed empty delta sign [Figure 2]. Hyper intensities suggestive of venous infarct were revealed by magnetic resonance imaging (MRI) [Figure 3]. Magnetic Resonance (MR) venography confirmed the diagnosis of cerebral venous thrombosis (CVT) [Figure 4].

Figure 1

Unenhanced CT brain showing ‘triangle sign’ (line)

Figure 2

Contrast-enhanced CT showing ‘empty delta sign’ (line)

Figure 3

MRI brain (T1-weighted) showing hyper intensities suggestive of venous infarcts

Figure 4

MR venography showing loss of normal flow void (line)

He was treated with low molecular weight heparin, Inj.mannitol, acetazolamide, Inj dexamethasone and insulin, later warfarin was added and titrated according to international normalized ratio (INR). He showed clinical improvement and discharged.

Most common venous sinus to develop thrombosis is the superior sagittal sinus followed by the lateral sinus (transverse sinus and sigmoid sinus), and cavernous sinus. The presentation is usually sub-acute, with symptoms evolving over days to weeks. Headache present in more than 90% of patients, is mostly diffuse, occasionally having thunderclap character mimicking subarachnoid hemorrhage. The other symptoms and signs include obscuration of vision, nausea, vomiting, papilledema, cranial nerve palsies, cerebral herniation and coma.[2]

It may be multifactorial and is variable in each patient. Each component of the Virchow's triad (endothelial damage, stasis and hypercoagulability of blood) may in turn have several causes to produce CVT.[3] In neonates, acute systemic illness, such as shock or dehydration, may be the cause. Frequent causes in older children include local infection, such as otitis media, mastoiditis, and coagulopathy. In adults, main risk factors are oral contraceptives, pregnancy, trauma, Crohn disease, sickle cell disease, tumor, protein C and S deficiency, paroxysmal nocturnal haemoglobinuria, diabetes mellitus, and nephrotic syndrome. Etiological factors are often subclinical forms of thrombophilic states occurring together, rather than the typical inherited and rare causes. Diagnosis is basically clinical, and the next step is to get a CT or MRI to look for supportive evidence of CVT and rule out other mimickers. The combination of an abnormal signal in a venous sinus and a corresponding absence of flow on magnetic resonance venography confirms the diagnosis of thrombosis.

CVT in a patient with diabetes has been reported very infrequently.[4] Patients with diabetes mellitus have a prothrombotic status, related to endothelial dysfunction, impaired fibrinolysis, increased coagulation factors and increased platelet reactivity, and turnover. Insulin resistance determines increased levels of the fibrinolytic inhibitor, plasminogen activator inhibitor-1 (PAI-1), the link between type 2 diabetes mellitus (DM) and fibrinolysis suppression. Furthermore, insulin resistance is associated with the increased expression and production of different coagulation factors promoting platelet adhesion to the vascular sub-endothelium. Insulin resistance affects the cellular phases of hemostasis, also impairing endothelial and platelet function, and endothelial-dependent vasodilatation.[56] CVT usually occurs only when several etiological factors come together incidentally. Our patient also might have developed sinus thrombosis with one or more acquired or genetically increased risk in addition to have type 2 DM.

CVT, a potentially life-threatening condition presents a diagnostic challenge. A high index of suspicion is essential. Diagnosis of CVT should be considered in all young patients with recent unusual headache even in absence of any predisposing factors. Prompt diagnosis improves the clinical outcome.