Epidural Blood Patch for Atypical Headache due to Spontaneous Intracranial Hypotension Associated with Meningeal Diverticulum

Editor, Spontaneous intracranial hypotension (SIH) is associated with cerebrospinal fluid (CSF) leak. Clinical manifestations of SIH are often non-specific and easily neglected. Multiple imaging tests are available for CSF leakage identification. In some cases, these test results are inconclusive. Hence, etiology of SIH CSF leak is often unidentified. The presence of meningeal diverticulum (MD) may be related to it. Empirically targeting spinal MD with epidural blood patch has been proposed recently.[1] It is challenging, especially in cases with doubtful CSF leak. Our case highlights a successful treatment strategy for intracranial hypotension associated with MD and a doubtful CSF leak by epidural blood patch. A 33 years old female presented with throbbing generalized headache of 25 days. Initially, there was no positional variation; the visual analog scale (VAS) was 7, which progressed to 9 in subsequent days. Headache was associated with nausea, vomiting, neck pain, low back pain, and loss of balance while walking. The patient also had complaints of generalized body pain with easy fatigability for a few months. There were no infective symptoms like fever, chills, skin rash, photophobia, sore throat, and cough, suggesting focal neurological etiology was present. A past history of chikungunya was present. The patient had undergone appendicectomy under spinal anesthesia 10 years ago. On examination, she was afebrile, with a pulse of 78/min and a blood pressure of 120/60 mm Hg. No orthostatic hypotension was present. Systemic examination and routine blood investigations were within normal limits. CSF examination showed proteins of 90.6 mg/dl and glucose of 56 mg/dl. CSF manometry showed CSF pressure of only 7 mmH2O (low), which created a suspicion of intracranial hypotension. Brain imaging studies showed diffuse pachymeningeal enhancement with distention of various sinuses, a bulky pituitary gland with a convex superior surface with a mamillopontine distance of 5.3 mm, a Ponto mesencephalic angle of 38 degrees, and an interpeduncular angle of 38 degrees, indicating spontaneous intracranial hypotension [Figure 1]. Magnetic resonance imaging (MRI) of the whole spine showed mild disc bulges at C3-C4, C4-C5, C5-C6, T1-T2, and T2-T3: L5-S1 with no nerve root compression.Figure 1: MRI brain showing pachymeningeal enhancementCT MYELOGRAPHY showed "doubtful leak at C1-C2 level", well-defined meningeal diverticula in bilateral L1-L2 neural foramina 6 × 4 × 3.2 mm (r) 6 × 4 × 4 mm (l)/extrathecal collection of contrast D2-D1. The maximum thickness of this collection was 3.8 mm. There were prominent nerve roots at D10-D11, D11-D12 on the right side and D12-L1 on both sides. Conservative treatment with analgesics, fluid resuscitation, and bed rest for 1 week was given. There was no improvement in symptoms, so epidural blood patch was administered in the sitting position by a landmark-guided technique. A Tuohys epidural 18 Gauge needle was inserted at L3-L4 Inter Vertebral Space (IVS). Under fluoroscopy with C arm guidance, the position of the needle was confirmed.[2] Slow CSF leak was noticed. Simultaneously, an autologous blood volume of 12 ml taken from the right upper arm was injected in aliquots of 4 ml every 1 min. 2cc saline mixed contrast was co-administered in between aliquots. The procedure was uneventful, and the patient was hemodynamically stable. Bed rest was advised for 24 h. Relief of symptoms was 20% on day 1 and day 2 and 40% from day 3 to 6, as described by the patient subjectively. Despite symptomatic improvement, the patient still had discomfort. Hence, a second epidural blood patch was done on day 7. In the prone position at L4-L5 IVS, 17 cc of right radial arterial blood was administered as all peripheral veins were thrombosed[3] [Figure 2].Figure 2: Administering epidural blood patch with under c arm guidance using Tuohys needleImmediately the next day, 60% relief of symptoms was reported, which progressed to 80% on day 9. The patient was discharged on day 15 with 95% relief of all symptoms and regain of normal physical activity. The patient was followed up for 2 years with no recurrence of symptoms, making the treatment successful. DISCUSSION Spontaneous leak of CSF presents a recognized cause of SIH in cases without a history of trauma or dural puncture. There are various theories proposed. The theory that the CSF volume loss might be the cause of SIH is supported by the fact that certain connective tissue disorders, such as Ehlers Danlos and Marfan's, are risk factors for SIH.[4] Another theory considered epidural hypotension as the main cause of SIH because epidural blood patch works by increasing the epidural space pressure, rather than sealing the CSF leak. Leakage at the level of the spine is regarded as the main cause of SIH with high incidence. Leak occurs via fragile areas of the dura mater and around nerve root sheaths or from the spinal thecal sac. Various dural weaknesses, either congenital or acquired, ranging from simple dural tears to multi-level complex MD, allow CSF to leak into the epidural space.[4] Sometimes, leakage can even happen via small defects due to slight trauma caused by severe exercise or a cough. Diverticula of the spinal nerve roots are thought to represent common sites where CSF leaks originate and a potential source of SIH.[5] The association between them is well established. A large number of surgically and radiologically proven cases of CSF leaks have been originating from abnormal spinal MD. Nevertheless, no direct leak is visualized at CT myelography, and MD may be the only finding. Interestingly, spinal diverticula were found to be significantly more numerous among patients with SIH with no leak seen on CT myelography, while their counterparts with SIH in whom a rapid leak was detected MD were less in number. This might be due to the difference in the etiology of fast leaks compared with slow or intermittent leaks. Technical factors such as underfilling or under-distension of diverticula in the presence of a rapid leak also contribute.[6] Clinical and imaging features of SIH are more varied than the stereotypical symptoms.[7] Like in our case, though imaging studies showed features of intracranial hypotension, there was no orthostatic nature or systemic hypotension. SIH is a rare but well-recognized cause of headache. Our patient fitted in the diagnostic criteria for SIH headache. Epidural blood patch (EBP) would be a definitive treatment for this MD-associated CSF leakage and SIH. The concept of EBP for treating post dural puncture headache was developed by Gormley in 1960. The "plug" hypothesis suggests that EBP results in the formation of a gelatinous plug at the site of dural leakage. This prevents further loss of CSF fluid. The subsequent production of CSF restores CSF pressure, improving headache. The "pressure patch" hypothesis suggests that injected blood increases epidural pressure, which compresses the dura mater and elevates subarachnoid CSF pressure. The mainstay of first-line interventional treatment for SIH is currently autologous EBP. Nevertheless, there is no systematic review of its efficacy in treating MD as yet. Empirically targeting spinal MD with BLOOD PATCH has been proposed recently. It is especially challenging in cases with doubtful CSF leak like the case presented above. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Author contribution Aparna A. Bagle: Procedural implementation, manuscript review -revising data of the manuscript critically for important intellectual content; final approval of the version to be published; Yashwant Nankar: Concept and design of study, clinical studies, procedural implementation; Ipshita Garg: Acquisition of data; Balkees Beevi Nazeer Ahmed: Drafting the article manuscript preparation and manuscript editing, literature search. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.