Decompressive hemicraniectomy for fulminant acute disseminated encephalomyelitis following dengue fever: Case report and literature review

Abstract

Background:

Acute disseminated encephalomyelitis (ADEM) is a rare immune-mediated demyelinating disorder of the central nervous system that typically occurs after viral or bacterial infections. Although most patients respond favorably to immunomodulatory therapy, a small subset develops fulminant ADEM characterized by malignant cerebral edema, refractory intracranial hypertension, and a high risk of mortality. Decompressive craniectomy has rarely been reported as a life-saving intervention in such cases.

Case Description:

A 25-year-old woman developed fulminant ADEM following dengue fever and initially presented with recurrent seizures progressing to status epilepticus. Brain magnetic resonance imaging demonstrated extensive bilateral demyelinating lesions involving the frontoparietal, occipital, temporal, and cerebellar white matter, with extension into the corpus callosum. Despite aggressive medical management, including high-dose intravenous methylprednisolone, osmotherapy, sedation, and plasma exchange, the patient experienced progressive neurological deterioration associated with diffuse cerebral edema, anisocoria, and radiological evidence of impending cerebral herniation. Owing to the failure of maximal medical therapy, a left decompressive hemicraniectomy was performed. The patient subsequently underwent additional immunomodulatory treatment, survived the acute phase of the disease, and demonstrated significant neurological recovery. A review of the literature identified nine previously reported cases of fulminant ADEM treated with decompressive craniectomy.

Conclusion:

Fulminant ADEM is an uncommon but potentially fatal neurological emergency. In cases complicated by malignant cerebral edema and refractory intracranial hypertension, decompressive craniectomy may represent a life-saving therapeutic option. Early recognition and timely surgical intervention appear to be associated with favorable neurological outcomes.

INTRODUCTION

Acute disseminated encephalomyelitis (ADEM) is a rare immune-mediated inflammatory demyelinating disorder of the central nervous system predominantly affecting children and young adults. The disease is typically characterized by a monophasic course and is commonly preceded by viral or bacterial infections, resulting in widespread inflammatory demyelination involving the brain and, occasionally, the spinal cord. Although the exact pathophysiological mechanisms remain incompletely understood, molecular mimicry and postinfectious autoimmune responses are believed to play central roles in disease development.[8,10]

Neurological manifestations are highly variable and may include encephalopathy, seizures, focal neurological deficits, ataxia, sensory disturbances, and altered levels of consciousness. Magnetic resonance imaging (MRI) usually demonstrates multifocal bilateral lesions affecting the cerebral white matter, deep gray nuclei, brainstem, or cerebellum. Most patients experience favorable outcomes following treatment with high-dose corticosteroids, intravenous immunoglobulin, or plasma exchange.[2]

A small subset of patients, however, develops fulminant ADEM, a severe clinical variant characterized by rapidly progressive neurological deterioration, diffuse cerebral edema, refractory intracranial hypertension, and impending cerebral herniation. This presentation is uncommon but carries substantial morbidity and mortality despite aggressive medical treatment.[9]

Decompressive craniectomy has been described as a rescue strategy for patients with fulminant ADEM and malignant cerebral edema. Although the available evidence is limited to isolated case reports, surgical decompression may provide life-saving control of intracranial hypertension and allow neurological recovery in carefully selected patients.[13]

Dengue fever is increasingly recognized as a cause of neurological complications, including encephalopathy, encephalitis, and postinfectious autoimmune disorders. Nevertheless, fulminant ADEM associated with dengue infection remains exceptionally rare, and reports requiring decompressive craniectomy are scarce in the literature.

Here, we report the case of a 25-year-old woman who developed fulminant ADEM following dengue fever complicated by diffuse cerebral edema and refractory intracranial hypertension requiring left decompressive hemicraniectomy. In addition, we review the published literature regarding the role of decompressive craniectomy in this rare and potentially fatal condition.

CASE REPORT

A 25-year-old woman with a history of hereditary sideroblastic anemia and secondary hepatosplenomegaly presented with recurrent generalized seizures over a 24-h period. Fifteen days before admission, she had experienced a febrile illness characterized by fever, myalgia, worsening anemia requiring blood transfusion, and subsequent severe headache, vomiting, and progressive neurological symptoms following dengue fever.

Upon admission, neurological examination revealed progressive encephalopathy and recurrent seizures with recovery of consciousness between episodes. She was subsequently admitted to the intensive care unit because of neurological deterioration requiring sedation and mechanical ventilation. Initial examination demonstrated preserved extraocular movements, mild nystagmus, and an extensor plantar response on the right side.

Initial neuroimaging raised concern for posterior reversible encephalopathy syndrome or ADEM. Brain MRI demonstrated extensive bilateral hyperintense lesions on fluid-attenuated inversion recovery (FLAIR) sequences involving the frontoparietal and occipital white matter, with additional involvement of the temporal lobes, cerebellar hemispheres, and corpus callosum [Figure 1]. The clinical history of recent dengue infection combined with the characteristic radiological findings favored the diagnosis of ADEM.

Figure 1:

Brain magnetic resonance imaging demonstrating extensive bilateral fluid-attenuated inversion recovery (FLAIR) hyperintensities consistent with acute disseminated encephalomyelitis. (a) Extensive bilateral frontoparietal white matter involvement. (b) Multifocal bilateral white matter lesions involving the frontoparietal regions, with involvement of the corpus callosum. (c) Posterior-predominant white matter lesions involving the occipital regions, with additional involvement of the temporal lobes and cerebellar hemispheres.

Despite intensive medical management, including sedation, osmotherapy, high-dose intravenous methylprednisolone pulse therapy, and subsequent plasma exchange, the patient’s neurological condition progressively deteriorated. Attempts to reduce sedation were unsuccessful, and serial examinations demonstrated hyperreflexia, bilateral extensor plantar responses, progressive anisocoria, and worsening level of consciousness.

Follow-up computed tomography revealed progressive diffuse cerebral edema with marked sulcal effacement and obliteration of the basal cisterns, consistent with malignant intracranial hypertension [Figure 2]. Clinically, the patient developed persistent anisocoria, with the left pupil larger than the right, indicating impending cerebral herniation. Given the radiological progression and neurological decline despite maximal medical therapy, decompressive surgery was recommended as a life-saving measure.

Figure 2:

Noncontrast computed tomography demonstrating diffuse cerebral edema with severe sulcal effacement, loss of normal cortical architecture, and obliteration of the basal cisterns, indicating malignant intracranial hypertension.

After discussion with the patient’s family regarding the severity of the condition, prognosis, and surgical risks, a large left frontotemporoparietal decompressive hemicraniectomy was performed as a life-saving procedure. Following dural opening, marked cerebral swelling was observed, confirming the severity of intracranial hypertension. Adequate hemispheric decompression was achieved, allowing expansion of the edematous brain and reducing the risk of impending cerebral herniation.

Postoperatively, the patient remained under intensive care, receiving continued pulse corticosteroid therapy and plasma exchange. Subsequent imaging demonstrated adequate decompression [Figure 3], while serial neurological examinations showed stabilization and gradual improvement of intracranial hypertension-related findings.

Figure 3:

Postoperative computed tomography following left decompressive hemicraniectomy demonstrating adequate hemispheric decompression and reduction of intracranial mass effect.

The patient survived the acute phase of the disease and underwent an intensive rehabilitation program. Progressive neurological recovery was observed during follow-up. At hospital discharge, she remained independent for most basic activities of daily living, although moderate limitations in instrumental activities persisted. No further episodes of neurological deterioration or recurrent demyelinating events were documented during follow-up. Written informed consent for publication was obtained from the patient and her family.

DISCUSSION

ADEM is a rare immune-mediated inflammatory demyelinating disorder of the central nervous system characterized by multifocal neurological deficits and encephalopathy, typically occurring after a viral or bacterial infection.[10] Although predominantly observed in children and young adults, ADEM may affect individuals of any age. The proposed pathophysiological mechanism involves an autoimmune response directed against myelin antigens through molecular mimicry, resulting in widespread inflammatory demyelination of the brain and spinal cord.[10]

Clinically, ADEM presents with a broad spectrum of neurological manifestations, including headache, fever, altered mental status, seizures, focal neurological deficits, sensory disturbances, ataxia, and motor weakness.[2,9] Most patients respond favorably to high-dose corticosteroids, intravenous immunoglobulin, or plasma exchange. However, a minority of patients develop fulminant ADEM, characterized by rapidly progressive cerebral edema, refractory intracranial hypertension, and impending cerebral herniation.[9]

Our patient developed neurological deterioration following dengue fever, initially presenting with recurrent seizures progressing to status epilepticus. Brain MRI demonstrated extensive bilateral FLAIR hyperintensities involving the frontoparietal and occipital white matter, temporal lobes, cerebellum, and corpus callosum, findings compatible with a severe inflammatory demyelinating process. Despite pulse methylprednisolone therapy and plasma exchange, the patient developed progressive diffuse cerebral edema, anisocoria, obliteration of the basal cisterns, and signs of malignant intracranial hypertension, ultimately requiring left decompressive hemicraniectomy.

Dengue-associated neurological complications are increasingly recognized; however, postinfectious ADEM remains an uncommon manifestation. Most published cases of fulminant ADEM have been associated with upper respiratory tract infections, influenza-like syndromes, Epstein–Barr virus infection, or nonspecific viral illnesses.[5,7,11,12] The association between dengue fever and malignant ADEM requiring decompressive craniectomy appears to be exceptionally rare and highlights the need to consider immune-mediated demyelinating disorders among the neurological complications of dengue infection.

The role of decompressive craniectomy in ADEM remains poorly defined because of the rarity of the condition. Nevertheless, the available literature consistently suggests that surgical decompression may be life-saving when intracranial hypertension becomes refractory to maximal medical management. Von Stuckrad-Barre et al. reported one of the earliest successful cases of decompressive hemicraniectomy for fulminant ADEM, demonstrating neurological recovery following surgical decompression.[13] Similar favorable outcomes were subsequently reported by Refai et al., Sekula et al., Ahmed et al., Dombrowski et al., Granget et al., Bourke et al., Algathani et al., and Azab.[1,3-7,11,12]

Our systematic review identified nine previously published patients treated with decompressive craniectomy for fulminant ADEM [Table 1]. Most reported patients were female, and ages ranged from 18 months to 51 years. A preceding infectious illness was documented in most cases. Common presenting symptoms included headache, seizures, impaired consciousness, focal neurological deficits, and progressive encephalopathy. Compared with these previously published cases, our patient presented similar radiological and clinical features but differed in that fulminant ADEM developed after dengue fever, an exceptionally uncommon trigger.

Table 1:

Reported cases of fulminant acute disseminated encephalomyelitis treated with decompressive craniectomy.

Interestingly, despite the severity of presentation, neurological outcomes were generally favorable following decompressive surgery. Several patients achieved complete neurological recovery, while others demonstrated meaningful functional improvement with only mild residual deficits. Among the reported cases, only one patient failed to demonstrate significant neurological recovery after surgical intervention.[4] Favorable neurological recovery was therefore observed in the vast majority of surgically treated patients, suggesting that decompressive craniectomy may substantially improve outcomes in carefully selected patients with fulminant ADEM complicated by refractory intracranial hypertension. The timing of surgery appears to be a critical determinant of outcome. In the majority of reported cases, decompressive craniectomy was performed only after failure of aggressive medical treatment, including corticosteroids, osmotherapy, sedation, hyperventilation, intravenous immunoglobulin, or plasma exchange.[1,3-7,11-13] Similarly, our patient underwent surgical decompression only after documented radiological progression, worsening cerebral edema, persistent anisocoria, and evidence of impending herniation despite immunomodulatory therapy and neurocritical care measures. These observations reinforce the concept that decompressive craniectomy should not be unnecessarily delayed once signs of refractory intracranial hypertension become evident.

The present case further supports the concept that decompressive craniectomy should be considered a rescue strategy in selected patients with fulminant ADEM complicated by malignant cerebral edema and refractory intracranial hypertension. Although evidence remains limited to isolated case reports, the consistency of favorable outcomes across published reports suggests that surgical decompression can provide a meaningful survival benefit and facilitate neurological recovery when instituted before irreversible secondary brain injury occurs.

This study is limited by its retrospective nature and the rarity of the condition. Furthermore, current evidence is restricted to isolated reports, precluding definitive conclusions regarding optimal surgical timing and patient selection. Nevertheless, the present case contributes additional evidence supporting decompressive craniectomy as a potentially life-saving intervention in fulminant ADEM. The favorable neurological outcome observed in our patient, despite severe cerebral edema and signs of impending herniation, reinforces the importance of early recognition and timely neurosurgical intervention when maximal medical therapy fails.

CONCLUSION

Fulminant ADEM is a rare but potentially fatal neurological emergency that may progress to malignant cerebral edema, refractory intracranial hypertension, and cerebral herniation despite aggressive immunomodulatory treatment. The present case highlights dengue fever as an uncommon trigger of fulminant ADEM and demonstrates the challenges associated with its management.

In our patient, progressive neurological deterioration and radiological evidence of diffuse cerebral edema persisted despite high-dose corticosteroid therapy and plasma exchange, ultimately requiring left decompressive hemicraniectomy. Surgical decompression was associated with survival and meaningful neurological recovery.

A review of the available literature demonstrates that decompressive craniectomy has consistently been associated with favorable outcomes in selected patients with fulminant ADEM complicated by refractory intracranial hypertension. Although current evidence is limited to isolated case reports, the accumulated experience suggests that early surgical intervention should be considered when maximal medical therapy fails, and signs of impending herniation are present.

Neurosurgeons and neurointensivists should be aware of this rare presentation, as timely recognition and prompt decompressive surgery may represent a life-saving strategy capable of improving both survival and long-term functional outcomes.

Ethical approval:

Institutional Review Board approval is not required.

Declaration of patient consent:

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for their images and other clinical information to be reported in the journal. The patient understands that the patient’s names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship:

Nil.

Conflicts of interest:

There are no conflicts of interest.

Use of artificial intelligence (AI)-assisted technology for manuscript preparation:

The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.

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