Traumatic chiasmal syndrome: a series of 19 patients

Abstract

Trauma is a rare cause of chiasmal syndrome. Patients with bitemporal field defects should be questioned about prior head injury. In the acute setting, magnetic resonance imaging is the most useful investigation. The treating practitioner should anticipate and treat associated endocrine, ocular motility, and other disorders. Mechanisms of damage to the optic chiasm after trauma include direct tearing, contusion haemorrhage and contusion necrosis. These mechanisms should not be considered mutually exclusive. Unilateral temporal hemianopia with a fellow blind eye is not necessarily the result of chiasmal disruption.

Hypopituitarism after traumatic brain injury

“…A recent retrospective review confirmed the low prevalence (2.9%) of diabetes insipidus in TBI patients admitted to the intensive care unit, and underlined that patients who developed the disease within the first 3 days after injury had a high mortality rate (68). By contrast, other authors demonstrated a high prevalence of diabetes insipidus during the acute phase post-TBI in patients admitted to a neurosurgical center (22 -26%) (49,69) and in patients with head injury damaging the chiasm (37%) (70). However, diabetes insipidus is frequently transient and can spontaneously disappear within a few days or up to 1 month (66,70,71) after the acute event, as confirmed by its low prevalence (0 -6.9%) in patients evaluated after months or years following TBI (5,6,69).…”

“…In the past, the risk of developing pituitary dysfunction was considered as strictly dependent on the severity of TBI, particularly when associated with skull and facial fractures, cranial nerve injury and a prolonged period of unconsciousness (64,76,78). It has also been reported that traumatic chiasmal syndrome is associated with impairment of anterior pituitary function in 10% of cases and permanent diabetes insipidus in 16% (70). The recent review by Benvenga et al (79) reported that 93% of patients with PTHP had suffered coma or unconsciousness following TBI.…”

Isolated Bitemporal Hemianopsia Due to Traumatic Chiasmal Syndrome

“…Visual acuity decreases to 20/40 or less in one or two eyes in about 85% of the patients, and total blindness in one eye occurs in about 50% of patients. [2,4] In the latter group, temporal hemianopsia is found in the sighted eye. Due to the close proximity of the cavernous sinus, the ocular motor nerves may also be injured.…”

“…[3] Frontal and/or basilar fracture is seen in about 70% of the patients and closed head trauma in 30%. [4] In the latter group, TCS is frequently associated with an intracranial hematoma. Other accompanying disorders may include cranial nerve palsies (anosmia, hearing loss, optic neuropathy, ocular motor palsy), cerebrospinal fluid leakage, pneumocephalus, meningitis, carotid aneurysm, carotid-cavernous fistula, nystagmus, and hormonal deficiencies.…”

“…One study has reported paralytic strabismus in 63% of the patients with TCS. [4] Permanent or transient diabetes insipidus develops in 30% to 50% of the patients, resulting from associated hypothalamicpituitary trauma. [2,4] In eyes with midline hemianopsia, the central macular visual field can be evaluated more sensitively by automated 10-2 or Amsler grid visual field tests.…”