Tentorial laceration may produce a tear in the vein of Galen, straight sinus, or transverse sinus. Occipital osteodiastasis consists of a separation between the squama occipitalis and the lateral portion of the occipital bone. Occipital osteodiastasis may result in rupture of the occipital sinus. Infratentorial subdural hematoma may present clinically 2 to 4 days after birth in a previously normal neonate. Signs of brainstem dysfunction, increased intracranial pressure, and nuchal rigidity may be present. The most frequent signs of brainstem dysfunction are skew deviation unchanged by caloric testing, asymmetric pupils, and bradycardia.

An inborn error of metabolism should be suspected in every comatose neonate. The level of suspicion should be raised if the neonate has: (1) a peculiar odor; (2) a combination of truncal hypotonia and limb hypertonia; (3) brainstem dysfunction; (4) signs of increased intracranial pressure; (5) stimulus-sensitive myoclonus; (6) abnormal respirations in the absence of cardiac or respiratory disease; or (7) a family history of unexplained death, metabolic disease, or parental consanguinity. A symptom-free interval lasting for a few days after birth may occur with some inborn errors of metabolism.
The blood, urine, and cerebrospinal fluid investigations that should be performed in a patient suspected of having an inborn error of metabolism include: (1) venous blood for CBC and platelets, liver function tests, glucose, lactate, pyruvate, ammonia, total and acylcarnitine, uric acid, biotinidase, and amino acids; (2) arterial pH; (3) urine for ketones, sulfite, and organic acids; and (4) cerebrospinal fluid for amino acids (especially glycine) and lactate.
Coma due to an inborn error of metabolism is produced by enzymatic defects in the metabolism of proteins, fats, carbohydrates, and pyruvate, or citric cycle abnormalities, mitochondrial respiratory chain, and urea cycle. These disorders can not be clinically distinguished from each other. Their diagnoses depend on specific laboratory findings.