Hypertrophic dura in 1 case

Patient Female, 47 years old
.
Intermittent convulsions for 1 year, with weakness in both lower extremities for 3 months, aggravated for 5 days and admitted to hospital
.
He has been diagnosed
with symptoms such as headache and convulsions with mental disorders as "subarachnoid hemorrhage", "organic mental disorder", and "epilepsy".

Physical examination: temperature 36.
2°C, blood pressure 100 mmHg/60 mmHg (1 mmHg = 0.
133 kPa).

Poor consciousness, nasolabial folds symmetry, normal muscle tone, normal tendon reflexes, no deep and shallow sensory impairment, negative meningeal irritation sign, and lumbar puncture showed colorless and transparent
cerebrospinal fluid.

Imaging: CT shows increased sickle density in the brain (Figure 1), and non-contrast MRI scan and enhancement reveals significant thickening of the meninges with orbital enhancement (Figure 2-4).

Fig.
1 Non-contrast CT scan showed a significant increase in sickle density in the brain

Fig.
2 Thickening of the dura mater on conventional T1 WI is an equisignal

Fig.
3,4 The dura mater is significantly strengthened uniformly on the contrast MRI scan, and the meninges are significantly thickened and strengthened in orbital positions in the coronal and axial positions

Diagnosis: (1) hypertrophic sclerosing meningitis; (2) Secondary epilepsy
.

It improved
after giving anti-inflammatory, hormonal, anti-epileptic, and nutritional symptomatic treatment.

Discuss:

Hypertrophic cranial pachymeningitis (HCP) is a rare disease
characterized by inflammatory fibrosis and hypertrophy of the dura mater and canopy, resulting in a series of neurological symptoms.
The cause and mechanism are still unclear, and the diagnosis mainly depends on tissue biopsy, and routine CT examination is easily confused
with diseases such as subarachnoid hemorrhage (SAH).

Clinical diagnosis is mainly based on clinical manifestations and MRI enhancement examination, and hormone therapy is more sensitive
.

HCP can be divided into two broad categories
, primary and secondary, according to the cause.
Those without a specific cause are called idiopathic or primary HCP; Microbial infections and autoimmune diseases are called secondary HCP
.
Usually secondary HCP is more common in primary HCP, and its infection sources include viruses and bacteria, caused by direct infection of the dura mater or adjacent infection involving the dura mater
.
Zhang Xinyu et al.
in China analyzed 8 cases of otogenic HCP and concluded that acute and chronic purulent otitis media can cause HCP secondarily, and it needs to be differentiated
from diseases such as subarachnoid hemorrhage in the canopy area.
This patient has a history of otitis media and supports the diagnosis
of HCP.

At present, it is mainly believed that HCP is a non-specific chronic progressive inflammatory response of the dura mater, and some patients with HCP also show dural reactive hyperplasia and hypertrophy
related to autoimmune factors.
The long course of HCP, headache, and multiple cranial nerve damage are the most common clinical manifestations
in patients with HCP.
Headache is mainly due to focal or diffuse dura, and a few can be caused
by concomitant cerebral edema and hydrocephalus.
The cranial nerves most commonly affected by this disease are the abductor nerve, followed by the trigeminal nerve, and then the optic nerve, oculomotor nerve, trochlear nerve, and facial nerve
.
Other clinical manifestations of HCP, such as epilepsy, ataxia, hearing loss, and changes in pituitary function, are mostly secondary to the involvement
of adjacent structures of brain tissue.
MRI is currently the best means of diagnosing HCP and is significantly superior to CT].

T1WI is a low or slightly lower signal, and T2WI is a significantly low signal
.
After enhancement, the hypertrophic dura mater is significantly strengthened, the dura mater is strengthened near the arachnoid side, and the dura mater is strengthened more specifically in the cerebellar screen and sickle of the brain, showing a characteristic "dual-track" strengthening
.

HCP is diagnosed in differential with the following conditions
.
(1) Subarachnoid hemorrhage: the patient has a sudden onset, severe headache, may have a history of trauma, and may not have a history of
otitis media.
CT showed increased density of lateral fissures, longitudinal cisterns, and sulcies, which could be identified by short-term reexamination without dural enhancement
.
(2) Meningeal metastases: there is a history of malignant tumors, dural thickening is irregular, and it is not difficult to identify
them in combination with the imaging features of metastases.
(3) Various types of meningitis mainly invade the pia mater
.
(4) Low intracranial pressure syndrome: postural headache, which can be distinguished
from this disease.

In conclusion, enhanced MRI and CT in patients with suspected HCP, combined with clinical features, are indispensable
for early diagnosis of HCP.