Unveiling the Possibility of Subclinically Present Congenital Hydrocephalus Triggered by Thalamic Hemorrhage in Late-onset Years: A Case Report

Abstract

Congenital hydrocephalus manifesting in old age is exceptionally rare. We present a case of hydrocephalus in an older woman, where congenital hydrocephalus was suggested following a thalamic hemorrhage. A woman in her 90s gradually developed gait and cognitive impairments. Eight months before her admission, she suffered a thalamic hemorrhage, after which she became bedridden and was transferred to our hospital following impaired consciousness from asphyxiation. Upon admission, her Japan Coma Scale score was 200. A head computed tomography scan revealed significant ventricular enlargement. A tap test was conducted to diagnose normal pressure hydrocephalus, resulting in a slight improvement in her Japan Coma Scale score to 20. Consequently, a ventriculoperitoneal shunt was performed. Two weeks after the ventriculoperitoneal shunt, her consciousness improved to a Japan Coma Scale score of 2, and she resumed oral intake. Two months after the surgery, head magnetic resonance imaging revealed tetraventriculomegaly, an open aqueduct, a wide foramen of Magendie, and a large cisterna magna. These findings raised the suspicion of previously undetected congenital hydrocephalus, exacerbated by panventriculomegaly with a wide foramen of Magendie and a large cisterna magna, revealed after the thalamic hemorrhage. At the final evaluation, she required only minimal assistance with oral intake, showing significant improvement not only compared with her condition before the ventriculoperitoneal shunt procedure but also to her state before the thalamic hemorrhage.

Introduction

Congenital hydrocephalus manifesting in old age is exceptionally rare. We report a case in which congenital hydrocephalus was suspected, triggered by a thalamic hemorrhage that developed in old age. Consent for this case report was obtained.

Case Report

A woman in her 90s had gradually developed gait and cognitive impairments but had never undergone intracranial evaluation, despite having an enlarged head circumference since she was young. Eight months before her transfer to our hospital, she suffered a left thalamic hemorrhage with ventricular perforation and significant ventricular enlargement with an Evans index of 0.40 (Fig. 1A). However, a head computed tomography (CT) scan taken at the time of onset revealed no evidence of ventricular obstruction, suggesting that the ventricular enlargement predated the hemorrhage. Two weeks later, a follow-up CT revealed further ventricular enlargement, with the Evans index increasing to 0.42 (Fig. 1B). Despite rehabilitation efforts, her activities of daily living (ADLs) remained impaired, making discharge to home difficult. Consequently, she continued to be hospitalized in a chronic care facility due to being bedridden and requiring significant assistance. The patient experienced choking while eating, leading to cardiopulmonary arrest. After suctioning foreign substances from her airway at the clinic, her heartbeat resumed. However, she remained severely disoriented with a Japan Coma Scale (JCS) score of 200, prompting her referral to our hospital. A head CT obtained upon admission revealed persistent ventricular enlargement, though the ventricles were slightly smaller compared to the subacute stage following the thalamic hemorrhage (Fig. 1C). In the coronal slice, ventricular enlargement was observed along with tight high convexity; however, there was no accompanying widening of the Sylvian fissure, allowing us to determine that the findings differed from those typically seen in idiopathic normal pressure hydrocephalus (iNPH) (Fig. 1D). As her consciousness did not improve post-admission and she remained in a vegetative state, we decided to perform a tap test to diagnose normal pressure hydrocephalus. A lumbar puncture was successfully performed at the L5/S1 level, draining 30 mL of cerebrospinal fluid (CSF). The opening pressure at the time of puncture was 13 cmH₂O. There were no abnormal findings in the CSF study. After CSF drainage, her alertness improved to a JCS score of 20. However, it was challenging to assess her gait and cognitive functions. Additionally, her consciousness did not improve sufficiently for oral intake training, and her severe pharyngeal dyskinesia further complicated the oral intake training. Given the patient's improvement with CSF drainage, we decided to proceed with a ventriculoperitoneal shunt (VPS).

Fig. 1

Head computed tomography (CT) taken before ventriculoperitoneal shunt.

(A) Head CT taken at the onset of a left thalamic hemorrhage revealed significant ventricular enlargement with an Evans index of 0.40 without evidence of ventricular obstruction.

(B) Two weeks later, a follow-up CT revealed further ventricular enlargement, with the Evans index increasing to 0.42.

(C), (D) Head CT obtained upon admission revealed persistent ventricular enlargement, though the ventricles were slightly smaller compared to the subacute stage following the thalamic hemorrhage. In the coronal slice, ventricular enlargement was observed along with tight high convexity; however, there was no accompanying widening of the Sylvian fissure, allowing us to determine that the findings differed from those typically seen in idiopathic normal pressure hydrocephalus (iNPH).

A VPS was performed under general anesthesia using a left posterior horn puncture and the Codman CERTAS^® plus programmable valve (Integra LifeSciences) set to a pressure setting of 5, corresponding to approximately 145 mmH₂O (Fig. 2). The patient's wakefulness gradually improved postoperatively, reaching a JCS score of 2, at 2 weeks after surgery, and oral intake training was initiated with a jelly diet once a day. Due to residual pharyngeal dyskinesia, oral haloperidol 0.75 mg/day was started, resulting in its resolution. The shunt pressure setting was gradually adjusted in a stepwise manner and eventually stabilized at a setting of 3, corresponding to approximately 80 mmH₂O. The ventricular size had decreased gradually (Fig. 3), and her level of consciousness stabilized, allowing her to consume oral intake three times a day and transfer to a wheelchair with full assistance.

Fig. 2

Head computed tomography (CT) taken after ventriculoperitoneal shunt placement (VPS).

The ventricular catheter was placed in the left lateral ventricle.

Fig. 3

Head computed tomography (CT) before and after ventriculoperitoneal shunt placement (VPS).

(A) On the head CT taken the day before surgery, marked ventricular enlargement is observed.

(B) Two weeks postoperatively, a reduction in ventricular size is noted. Gradual adjustments to the pressure settings were made.

(C) By 1 month after surgery, the ventricular size had decreased to a level comparable to that observed at the time of the thalamic hemorrhage.

At 2 months postoperatively, a head magnetic resonance imaging (MRI) showed destruction of the sella turcica, tetraventricular dilatation, patency of the aqueduct with flow void, and a wide foramen of Magendie with a large cisterna magna (Fig. 4). We diagnosed the patient as having a possible case of subclinically present congenital hydrocephalus due to panventriculomegaly with a wide foramen of Magendie and a large cisterna magna (PaVM), which had not been diagnosed previously. Following the thalamic hemorrhage, symptoms of normal pressure hydrocephalus became evident. After the VPS procedure, her ADL status had improved sufficiently to allow her to live in a reclining wheelchair. Furthermore, she required only minimal assistance with oral intake, showing marked improvement, not only compared with her condition before the VPS procedure but also by becoming able to enjoy conversations, a notable improvement from her condition before the onset of the thalamic hemorrhage. Finally, she was discharged to a special care home on postoperative day 74.

Fig. 4

Head magnetic resonance imaging (MRI) performed 2 months after ventriculoperitoneal shunt (VPS).

(A) T1-weighted imaging shows enlargement of lateral ventricles. (B) An axial slice of fast imaging employing steady-state acquisition (FIESTA) shows membranous tissue in the paramedian area of the prepontine cistern, which is indicated by the red arrow. (C) A sagittal slice of T2 weighted image reveals the destruction of the sella turcica, enlargement of both the third and fourth ventricles, an opening aqueduct with flow void, a wide foramen of Magendie, and a large cisterna magna.

Based on these MRI findings, the patient was diagnosed with a possible panventriculomegaly with a wide foramen Magendie and large cisterna magna (PaVM).

Discussion

Congenital hydrocephalus manifesting in old age is exceptionally rare. Delayed onset of congenital or developmental origins include long-standing overt ventriculomegaly in adults (LOVA),¹⁾ and PaVM.²⁾ In cases of significant ventricular enlargement, indicated by an Evans index of 0.40 or higher, pathologies other than iNPH should be carefully considered.^3,4) In this case, significant ventricular enlargement was already present at the onset of the left thalamic hemorrhage, despite the absence of an obstruction within the ventricular system. This observation suggests the possibility of a latent component of congenital hydrocephalus. While prolonged impaired consciousness and dysphagia might initially appear to be solely attributable to the thalamic hemorrhage, it is more plausible that these symptoms were significantly influenced by an underlying brain vulnerability associated with congenital hydrocephalus.

Kageyama et al.²⁾ proposed MRI diagnostic criteria for PaVM, including¹⁾ tetraventricular dilatation,²⁾ visualization of the aqueduct with flow void on T2-weighted images, and³⁾ a wide foramen of Magendie and large cisterna magna. In this case, all of the diagnostic criteria outlined above were fulfilled, and the patient was considered to have a possible case of PaVM. However, certain features resembling Blake's pouch cyst (BPC) were also observed. The diagnostic radiological features of BPC are as follows:¹⁾ tetraventricular hydrocephalus,²⁾ infra- or retrocerebellar localization of the cyst,³⁾ relatively well-developed, nonrotated cerebellar vermis,⁴⁾ cystic dilation of the fourth ventricle, and⁵⁾ some degree of compression on the medial cerebellar hemispheres.⁵⁾ Generally, PaVM is classified as communicating hydrocephalus, while BPC is categorized as non-communicating hydrocephalus. In this case, the patient's level of consciousness improved following CSF drainage, which was considered a clear positive response to the tap test. Consequently, a diagnosis of PaVM was made. In contrast, Cornips et al.⁶⁾ reported six cases of BPC, but in two adult cases, no definitive membranous structure was identified. It is speculated that these cases might represent findings more consistent with PaVM. Additionally, there has been a case report of BPC in which the membrane of BPC contained small perforations, indicating that the membrane in the case was incomplete.⁷⁾ These findings suggest that it may be challenging to clearly distinguish between PaVM and BPC based solely on imaging findings. According to previous reports, PaVM and BPC, when manifesting in adulthood, typically present with symptoms such as headache, cognitive impairment, and gait disturbance, which are often similar to each other.^2,5) Sagittal fast imaging employing steady state acquisition (FIESTA) is crucial for diagnosing PaVM, and LOVA.^3,8,9) Additionally, the destruction of the sella turcica on sagittal FIESTA reflects chronic intracranial hypertension, and the downward depression of the third ventricle on FIESTA can be used to determine the indication for endoscopic third ventriculostomy (ETV). However, ETV can be challenging in some PaVM cases due to a tough arachnoid in the prepontine cistern or an enlarged fourth ventricle with brainstem deviation toward the clivus and a narrow prepontine cistern. Furthermore, the presence of scarring in the prepontine cistern, as seen in this case, has been reported as a risk factor for the failure of ETV.¹⁰⁾ Therefore, VPS was indicated for the initial treatment of this patient. The evaluation of CSF dynamics using Time Spatial Labeling Inversion Pulse (Time-SLIP) is crucial for understanding pathology and determining appropriate treatment strategies. Kageyama et al.²⁾ reported that in cases of PaVM associated with downward bulging of the third ventricular floor, CSF flow into the prepontine cistern was restricted.²⁾ In contrast, cases without this feature exhibited CSF flow into the prepontine cistern. Furthermore, they demonstrated that ETV is effective in cases where CSF flow into the prepontine cistern is restricted.²⁾ In the present case, however, the Time-SLIP evaluation could not be performed due to technical limitations. The Time-SLIP method has yet to be fully standardized, and its implementation and interpretation remain inconsistent across facilities, highlighting a significant current limitation.

In this case, significant clinical improvement was observed, probably attributable to the unique pathophysiology of normal pressure hydrocephalus. The rapid manifestation of normal pressure hydrocephalus following the thalamic hemorrhage suggested a compromised CSF circulation. Additionally, the destruction of the sella turcica indicated that the patient was in a state of chronic intracranial hypertension due to PaVM, which resulted in a decline in ADLs even before the thalamic hemorrhage occurred. VPS not only alleviated normal pressure hydrocephalus post-thalamic hemorrhage but also potentially improved the aggravated congenital hydrocephalus condition.

Congenital hydrocephalus may not always present with classic Hakim's triad symptoms (gait disturbance, cognitive impairment, and urinary disorders), but also with features such as decreased intelligence, headaches, psychiatric symptoms, balance issues, visual impairments, and parkinsonism.^3,4,11) Delayed diagnosis can lead to severe symptoms such as vegetative state, immobility, and apathy.⁴⁾ When marked ventricular enlargement suggests congenital hydrocephalus, comprehensive evaluation of associated clinical symptoms and consideration of therapeutic intervention are crucial. The prevalence of congenital hydrocephalus presenting in old age remains unclear due to its rarity. However, with the dissemination of the guidelines for the management of iNPH (third edition),¹²⁾ opportunities for diagnosing iNPH are expected to increase. Concurrently, the diagnosis of congenital hydrocephalus with onset in old age is also anticipated to rise. It is imperative not to diagnose "normal pressure hydrocephalus" hastily, as in cases with significant ventricular enlargement (Evans index >0.40), but rather to make informed treatment decisions based on a thorough review of imaging findings, pathophysiology, and CSF dynamics. Even in very elderly patients with severe conditions and significant ventricular enlargement, as seen in this case, if findings suggestive of congenital hydrocephalus are present, it may be worthwhile to consider CSF shunt surgery based on the results of the tap test.

We encountered a case of hydrocephalus that was potentially indicative of preexisting PaVM, unveiled by a thalamic hemorrhage in late-onset years.

Conflicts of Interest Disclosure

There are no conflicts of interest.

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