A Rare Cause of Headache in Emergency Department – Porencephalic Cyst

INTRODUCTION

Porencephaly is an extremely rare cephalic disorder involving encephalomalacia (1). Its etiology remains not entirely elucidated and manifests as a neurological condition affecting the central nervous system (2). This condition is characterized by cysts or cavities in the cerebral hemisphere, representing a neurological disorder of the central nervous system (3).

Here, we presented a case of a porencephalic cyst, which is a rare cause of headache in adults.

CASE

A 25-year-old male patient presented to our emergency department with a recent onset of headache. On arrival, his Glasgow Coma Scale (GCS) was 15, vital signs were stable, and he had no fever. Physical examination did not reveal neck stiffness, and cranial nerve examinations were normal. There was no evidence of an infectious focus in the patient. Brain computed tomography (CT) imaging revealed asymmetric enlargement in the left lateral ventricle, with a hypodense lesion extending towards the left supraventricular level adjacent to the lateral ventricle (Image 1,2 and 3). The CT report indicated no midline shift. The patient was consulted to the Department of Neurosurgery. The consultation resulted in the diagnosis of a porencephalic cyst based on the CT findings, with no evidence of edema or midline shift. Since no urgent pathology was identified, the patient was discharged with recommendations for outpatient follow-up at the Neurosurgery Clinic, with a Brain MRI requested. The patient benefited from analgesic treatment in the emergency department and was discharged with instructions.

Image 1,2 and 3.

DISCUSSION

Porencephaly was coined by Heschl in 1859 to describe a cavity within the human brain (4). The term “porencephaly” is derived from Greek roots, meaning “holes in the brain” (5). It represents a cavity within the cerebral hemisphere with a smooth wall covered by gliotic or spongy white matter, containing cerebrospinal fluid. Typically, the cavity communicates directly with the ventricular system and is often found in regions supplied by cerebral arteries. In other instances, it may be separated by a thin layer of brain tissue and covered externally by the arachnoid (2). These cysts and cavities are often the result of destructive (encephaloclastic) processes but can also arise from abnormal development (malformation), direct injuries, inflammatory processes, or hemorrhages (6). The prevalence is approximately 3.5 per 100,000 live births, with very rare reports in adults (2,7).

The cavities can vary significantly in size and location; they can be cortical or subcortical, unilateral or bilateral, single or multiple. Porencephalic cysts can be classified as congenital or acquired: it has been suggested that they are triggered by a vascular supply disorder leading to cerebral degeneration. Congenital porencephalic cysts result from intrauterine vascular injury leading to cerebral ischemia or intra-parenchymal hemorrhage. Acquired porencephalic cysts are secondary to injuries occurring later in life, such as trauma, surgery, ischemia, or infection (2). In childhood, undiagnosed head trauma can result in the widening of the fracture line over time, leading to the formation of a leptomeningeal cyst that can eventually merge with the ventricle towards adulthood, forming a porencephalic cyst (8).

Cysts and cavities can cause a variety of symptoms. The symptoms of porencephaly vary depending on neuronal loss following cyst formation or the mass effect of the cyst itself (2). In the literature, psychiatric disorders such as seizures, visual, speech, and hearing impairments, rhinorrhea, otorrhea, schizophrenia, and psychosis have also been reported (9,10).

In diagnosis, Brain CT scan reveals an intracranial cyst with well-defined borders and central hypodensity attributed to cerebrospinal fluid. Mass effect on adjacent parenchyma is usually not observed, although very large cysts may locally cause such effect. Brain Magnetic Resonance Imaging (MRI), along with cerebrospinal fluid signal, may depict a well-defined cyst within the brain parenchyma covered by white matter. Neurosurgical treatment is reserved primarily for symptomatic patients, such as those with drug-resistant epileptic seizures. There is no literature discussing treatment for asymptomatic porencephalic cases that require only monitoring (2).

REFERENCES:

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