a 2-year - old boy was transferred to the emergency department approximately 4 hours after having severe head trauma with loss of consciousness . on physical examination
, he had a right temporoparietal scalp laceration and subgaleal hematoma ; the child had a status of decerebrate rigidity .
brain ct showed intraventricular hemorrhage and subarachnoid hemorrhage ( figure 1a ) . a , head computed tomography ( ct ) illustrating the intraventricular hemorrhage .
b , postoperative intraventricular external drainage resulted in a significant decrease in the intraventricular hemorrhage .
c , enlargement of both the lateral ventricles with surrounding white matter edema is consistent with communicating hydrocephalus .
f - i , axial and sagittal ct images showing severe , bilateral thickening of the inner table of the frontal bone with cortex compression .
i , the outer table of the frontal bone was intact . an external ventricular drain was performed .
one week after surgery , cranial ct revealed that the ventricle hemorrhage had disappeared ( figure 1b ) , and the drain tube was removed .
one month later , repeat head ct showed dilation of the entire ventricular system associated with communicating hydrocephalus ( figure 1c ) .
his consciousness was gradually recovered , and he was awakened 2 months later . the patient was discharged . at 2-year follow - up , he showed hypophrenia and dysphasia , which was diagnosed according to the diagnosis criterion of mental retardation established by the world health organization in 1985 and the  s - s checkup list of dysphasia . 
the neuroimaging findings revealed that the lateral ventricles were smaller than before ( figure 1e ) .
five years after surgery , the child was readmitted to our department due to headache , vomiting , imbalance , inappropriate behavior , and loss of interest .
the patient had not developed a frontal extra - axial hemorrhage in the past 5 years .
there was bilateral optic disc swelling , with hemorrhages of the optic nerve head and surrounding retina ( figure 2a ) .
serum cortisol , prolactin , progesterone , estradiol , t3 , t4 , thyroid - stimulating hormone , and glucose tolerance test were within the normal limits .
brain ct showed severe , bilateral thickening of the inner table of the frontal bone with cortex compression ( figure 1f - i ) .
the inner table was honeycombed and red ( figure 2b and c ) , and the intracranial pressure was elevated . to achieve the decompression , a complete resection of the mass was performed , and the dura was opened in a star fashion .
three - dimensional image formation was used to shape the titanium mesh for the skull neoplasty .
the mass was immersed in formalin for study of the histological appearance of the mass with mineralized lamellar bone .
the forehead had a good contour , and postoperative radiographs demonstrated that the bone grafts remained intact and no evidence of recurrence of the mass .
baseline radiography of the skeletal system was performed and showed no additional foci of hyperostosis ( figure 3a - c ) .
a - c , postoperative brain computed tomography ( ct ) demonstrating that the frontal bone was removed and replaced with titanium mesh to relieve the brain compression .
hyperostosis frontalis interna is an overgrowth of bony tissue in the inner plate of the frontal bone and has been documented in the medical literature for over 300 years .
the estimated incidence of hyperostosis frontalis interna in the general population is 5% to 12% .
hyperostosis frontalis interna has not been reported in an asymptomatic patient younger than 10 years of age ; hence , the present patient is the first case in the medline database .
the most acceptable hypothesis regarding hyperostosis frontalis interna etiology is hormonal influence on bone growth .
for example , estrogen stimulation could play a part in the emergence of hyperostosis frontalis interna and explain its predominance among females . in our case ,
the hormone levels were normal , and interestingly , the hyperostosis frontalis interna was found after severe trauma . with the existing findings , it is difficult to address whether the trauma was related to hyperostosis frontalis interna . to the best of our knowledge ,
there have been no previous reports in the literature associating hyperostosis frontalis interna with brain trauma .
the associated signs and symptoms are generally nonspecific and benign , but they can cluster together in some cases , giving rise to various syndromes .
the most frequently presented complaints were morgagni syndrome ( headache , obesity , virilism , and hypertrichosis ) , stewart - morel syndrome ( obesity and neuropsychiatric symptoms ) , and troell - junet syndrome ( acromegaly , toxic goiter , and diabetes mellitus ) .
our patient had imbalance which , to our knowledge , has not been mentioned previously . in some severe cases ,
hyperostosis frontalis interna leads to compression of soft tissue , dural irritation , and brain atrophy because of the thickening of the skull and decrease in the intracranial volume .
it has been established that hyperostosis frontalis interna can cause diverse psychiatric disturbances such as aggressiveness , paranoia , or depression .
our case tends to confirm that due to extensive hyperostosis frontalis interna , frontal lobe compression can lead to cognitive impairment and psychiatric disorders .
the clinical symptoms and signs indicated the elevated intracranial pressure , which was not described in all the previous reports .
hyperostosis frontalis interna is commonly an incidental finding in x - ray , ct , and mri studies .
computed tomography scans , which provide the radiologist with enough information to distinguish hyperostosis frontalis interna from other bony growth , are better diagnostic tools for hyperostosis frontalis interna . in our case , the authors found bilateral frontal inner tables with diffuse uneven thickening .
histologically , the process of hyperostosis frontalis interna is thought to be a deposition of new bone primarily on the inner table and a progressive development of diploe .
hyperostosis frontalis interna is characterized by remodeling of the inner table of the frontal bone into a cancellous phenotype .
hyperostosis frontalis interna is a benign process , and the majority of patients appear to be asymptomatic ; thus , conservative observation can be used in these cases .
if hyperostosis frontalis interna leads to headaches , neurologic symptoms , psychiatric disorders , and cognitive impairment , the surgical excision of the thickened portion of the bone is the only method of treatment to relieve the symptoms .
postoperatively , the patient had an uneventful recovery , and the cognitive impairment was improved .
hyperostosis frontalis interna is currently regarded as an independent entity and starts to appear at a much younger age .
the authors described a case in a 7-year - old boy , presenting imbalance , cognitive impairment , headache , vomiting , and papilledema with hemorrhages ; this is the first such case reported in the literature .
the etiology , however , remains unclear , and it is difficult to prove the correlation between hyperostosis frontalis interna and brain injury . if present , the surgical decompression can be an effective treatment method .
our case confirms that the clinical presentation was elicited due to compression of the involved cortex area .
 hyperostosis frontalis interna is an unexplained irregular thickening of the inner table of the frontal bone . 
 hyperostosis frontalis interna was first identified in 1719 by morgagni as a symptom of a more generalized syndrome characterized by virilism and obesity . 
 most current studies have shown hyperostosis frontalis interna to be a sex- and age - dependent phenomenon , and females manifest a significantly higher prevalence of hyperostosis frontalis interna than males . in this article , the authors report the clinical case of hyperostosis frontalis interna in a 7-year - old child who had severe traumatic brain injury in the past ; review the related literature ; and discuss the clinical , radiological , and therapeutic features of this condition . 
Case Report
Discussion
Conclusion