Keywords
cerebral contusion - headache - hygroma - intracranial hypotension - SDH - traumatic
IH
Introduction
Cerebrospinal fluid (CSF) provides buoyant support to the brain and the spinal cord.
According to the Monroe–Kellie doctrine, confined space in the cranium causes any
change in CSF volume contributing to significant intracranial pressure (ICP) changes,
which cause a variety of pathologies and symptoms.[1]
[2]
The symptoms of the patient in both conditions, that is, elevated or reduced ICP,
are the same including postural headache, neck retraction symptoms, and bradycardia;
the incidence of increased intracranial tension following brain surgeries is significantly
higher compared with the occurrence of intracranial hypotension (IH).[3] However, once recognized, IH is relatively easier and faster to treat compared with
intracranial hypertension with complete resolution.
We, hereby, present a case of motorcycle road traffic accident (RTA) with subdural
hematoma (SDH) like presentation, clinically and radiologically but re-evaluated and
diagnosed as traumatic IH and successfully surgically managed, thereafter.
Case Report
A 33-year-old gentleman presented to us with a history of persistent holocranial headache
for the past 1 month along with neck pain. A history of falls from a motorcycle in
an RTA was reported 1 month before the onset of symptoms. There was no loss of consciousness,
seizures, or any significant symptoms during 72 to 96 hours of trauma, after which
the above-mentioned complaints emerged. The headache was holocranial, mild to moderate
in intensity, dull aching, continuous, not relieved with medication with the severity
of pain gradually increasing, more in the occipital region, aggravated by sitting
and standing, and improved by lying down and taking rest. It was not associated with
any nausea, vomiting, or vision abnormalities. The patient also complained of simultaneous
complaint of neck pain, which was continuous and nonradiating, with no aggravating
factors, partly relieved with medication (for which an X-ray of the skull and cervical
spine was done, which was normal).
Upon examination, the patient was drowsy and disoriented and did not respond to medications.
His Glasgow Coma Scale (GCS) score was 08/15 and his vital signs were stable. His
fundus was normal with no signs of papilledema. His bilateral pupils were normal in
size and normally reactive to light. The extraocular movements in both eyes were full.
No motor or sensory deficit was elicited. There were no signs of meningeal irritation.
Admission MRI of the brain and cervical spine was reported as bilateral SDH with mass
effect ([Fig. 1]) showing tonsillar herniation approximately 9.2 mm below McRae's line and mild brainstem
herniation. The patient was planned for burr hole and drainage. But upon re-reading
the MRI films, along with bilateral extra-axial subdural collections, a droopy penis
sign ([Fig. 2]; splenium of the corpus callosum sagging downward) was seen. Hence, a repeat cranial
MRI was performed and diffuse pachymeningeal enhancement of the dura with engorged
dural venous sinuses was noted ([Fig. 3]), along with previous findings. MRI of the cervical spine was screened again and
a focal CSF collection between the posterior elements of C1 and C2 with a focal discontinuity
in the cortical outline of lamina was seen, which suggested a dural tear ([Figs. 4] and [5]).
Fig. 1 Bilateral extra-axial subdural collections with mass effect.
Fig. 2 Droopy penis sign seen on T2-weighted sagittal MRI of the brain.
Fig. 3 Diffuse pachymeningeal enhancement of the dura with engorged dural venous sinuses
in T2-weighted sagittal section of MRI of the brain.
Fig. 4 Focal cerebrospinal fluid (CSF) collection between the posterior elements of C1 and
C2 with a focal discontinuity in the cortical outline of lamina suggestive of dural
tear.
Fig. 5 T2 axial section at the C2 level showing dural tear.
So, the International Classification of Headache Disorders, 3rd edition (ICHD-3),
was referred to and the diagnostic criteria for headache and MRI findings attributed
the diagnosis to spontaneous IH. The patient was then kept on continuous intravenous
(IV) fluids, oral theophylline, oral caffeine, and oral nonsteroidal anti-inflammatory
drugs (NSAIDs). But the headache did not improve. Hence, surgical intervention was
planned. Owing to the immediate unavailability of an epidural blood patch, laminectomy
followed by duraplasty was done. Twenty-four hours after surgery, the patient's symptoms
had significantly improved, even in the supine and standing posture. Hence, it was
diagnosed as a case of traumatic IH.
Discussion
IH was described for the first time in 1953 as “hypotension of the cerebral fluid”
by the German neurologist Georges Schaltenbrand.[4] The cardinal symptom of IH is described as postural headache usually aggravating
in the upright position and improving in the supine or Trendelenburg position.[3]
There are well-defined diagnostic criteria for spontaneous IH based on clinical and
radiological signs.[5] The three main sources for CSF leak are a tear of the spinal dural membrane, rupture
of a meningeal diverticulum, and development of a CSF venous fistula. Brain MRI with
gadolinium is the most sensitive test for identifying spontaneous IH. Generally, it
is difficult to detect the causative CSF leakage. The location of CSF leaks associated
with spontaneous IH is almost exclusively spinal, mostly occurring at the thoracic
or cervicothoracic junction, in the form of epidural fluid collections, collapse of
the dural sac, engorgement of the epidural venous plexus, and meningeal diverticula.
Additional neuroimaging when initial studies are nondiagnostic are noninvasive MR
myelography and radioisotope cisternography.[6] Common CSF abnormalities in patients with spontaneous IH include a low CSF opening
pressure, moderate lymphocytic pleocytosis (up to 50 cells/mm3), the presence of red blood cells, and elevated protein (commonly up to 100 mg/dL).
The CSF pleocytosis likely reflects a reactive phenomenon secondary to hydrostatic
pressure changes.
Hygromas are believed to be compensatory enlargement of the subdural space due to
the loss of CSF volume. The true mechanism of the development of SDH or hygroma due
to IH is yet to be hypothesized. However, it has been provisionally described, first,
by a rupture of the bridging veins by being pulled away from the dura because of the
low ICP and brain descent or, second, by bleeding from the enlarged veins in the subdural
zone, which may explain the development of an SDH8. Many prior cases in the literature
are shown to have treated the patient with immediate burr hole and decompression of
SDH, but this paradoxically worsens the patient due to further lowering ICP. A similar
outcome would have happened in our case if the dural tear had not been identified
and the patient had been taken up for SDH management.[7]
[8]
Typical treatment in the context of spontaneous IH is a noninvasive conservative approach
including bed rest in the Trendelenburg position, steroids, hydration, and abdominal
binder. Additionally, IV or oral caffeine due to the vasoconstrictive effect and stimulation
of the CSF production may be beneficial. As an alternative, an intervention is recommended,
consisting of epidural blood patches or surgical repair of the leakage as in our case.
Conclusion
The causes of prolonged postconcussion headaches are often unidentified, of which
IH caused by a CSF leak is potentially under-recognized and, more so, under-reported.
It should be a differential diagnosis for a case of mild or moderate trauma in association
with prolonged postural or permanent headache who is displaying symptoms similar to
raised intracranial pressure and a history of significant cervical torsion should
be considered for traumatic IH and MRI should be considered relatively early. In such
cases, bilateral SDH with mass effect must be ruled out of any CSF leak before attempting
the lifesaving decompressive surgery as it may paradoxically lead to further morbidity
and mortality of the patient.
