Anatomical and physiological differences between children and adults contribute to differences in clinical presentations. The pediatric cranium is elastic. In infants, the cranium consists of thin bone lamellas joined by connective tissue (periosteum and dura). These junctures calcify and the seams become gradually stronger. Parallel with the closure of the seams, the cranium becomes less elastic. In the earliest pediatric years, but to a gradually decreasing degree, the expanding cranium will often compensate for an increasing intracranial volume, and thereby compensate for the pressure increase one would experience with an adult tumor. In this way, the development of clinical symptoms are postponed and subdued.
Intracranial tumors in children often grow slowly. The symptoms are insidious and vague. "Doctor's delay" is often very significant in this patient group. Since tumors in children are often localized to the posterior cranial fossa, it is important to be familiar with clinical symptoms and signs of a tumor in this area of the intracranial space.
From the posterior cranial fossa, symptoms are often due to exogenous factors or an injury to local structures (cerebellum, cranial nerves, or brain stem) combined with a general increase in intracranial pressure, due to obstruction of brain fluid drainage and hydrocephalus. Often, the clinical signs of increased intracranial pressure dominate, while the focal neurological signs are less prominent.
In infants in the first year of life, an abnormal increase in head circumference measured at the public health clinic may be the only finding.
In older children, the first symptom is often headache, usually occurring gradually over a longer period of time, and becoming most significant in the morning. Symptoms are reinforced when the child has been lying flat for many hours. Thus, the child may awaken late at night with a headache. The pain may be localized to the neck/back of the head, or may be more diffuse.
Further on in the course of the disease, symptoms are often nausea and projectile vomiting. In advanced stages, the child usually experiences disturbances in consciousness, cranial nerve palsies and eventually, herniation and death. Papillary edema is often present at the time of diagnosis.
If there is damage to cerebellar structures or neuronal tracts in the brain stem, unsteadiness is an early clinical sign.
If there is invasion of the brain stem, diplopia and nystagmus are common symptoms. Bulbar palsy with dysarthria and impaired swallowing is also observed with infiltration into the brain stem. In advanced stages, this can also lead to hemiparesis.
Abnormal positions of the head/neck can reflect pain from the posterior cranial fossa. Torticollis can therefore be an early clinical sign of a lateral small brain tumor with invasion of the accessory nerve. It is not rare for patients with this symptom to be treated by a physiotherapist before the diagnosis is made. Also, stiffness of the neck can be present, which is a threatening sign of herniation of the cerebellar tonsils, or due to pressure and stretching of the brain membranes.
Supratentorial tumors may cause symptoms and signs in the form of:
- epileptic seizure from increased intracranial pressure
- focal-neurological dysfunction
- changes in personality
- endocrine disturbances
Over half of children with tumors in the cerebral hemisphere initially present with epilepsy. Changes in personality and behavioral disturbances are common for tumors in the frontal region.
For tumors in the hypothalamic area, the so-called diencephalic syndrome may be observed:
- vision disturbances
- weight loss
Hypothalamic tumors can also cause disturbances in hunger/fullness regulation as a characteristic symptom.
Endocrine disturbances are common with suprasellar/hypothalamic tumors. Lack of growth hormone is typical for craniopharyngiomas.
Sometimes, a sunset gaze with upward gaze paresis may be seen due to a general increase in intracranial pressure. This is probably due to compression of the lamina quadrigemina. The same is observed in tumors originating from the pineal region where the characteristic Parinauds syndrome occurs occasionally: gaze paresis, squinting, and disturbance of pupillary reflexes.
Supratentorial tumors can cause hydrocephalus from obstruction of cerebrospinal fluid drainage through the third ventricle or interventricular foramen. An increase in intracranial pressure in children can cause diastasis of the skull's sutures (suture rupture), which can cause an abnormal sound at percussion of the cranium, or "cracked-pot sound." This test is performed by percussing one side of the cranium, with the examiner's ear is located on the skull on the opposite side.