Symptoms Following MTBI: Part III

Balance and spatial disorientation problems may be related to vestibular dysfunction, vision disturbances, perilymphatic fistulas or hydrops (inner-ear edema), and/or other sensory integration deficits.

Definition: Vestibular system in the middle ear which senses movements of the head. Disorders of the vestibular system can lead to dizziness, poor regulation of postural muscle tone and inability to detect quick movements of the head.

Definition: Location of paralymphatic fistula (hole) near the stapes and vestibule areas between the semi-circular canals and cochlea.

Vision disturbances are frequently unrecognized after MTBI. Even with persistent complaints from the person, proper assessment is often not pursued by the clinician. Disturbances in eye movement, acuity, and/or visual perception can be common contributors to headaches, task avoidance, and fatigue.

[ Illustration of Visual System and Deficits ]

Altered taste and smell are also frequently unrecognized after MTBI. Facial fractures should be a cue to perform a chemosensory evaluation to rule out this dysfunction. Fractures may cause obstruction of nasal passages and/or damage to the sensory bulbs of cranial nerve I (the olfactory nerve) at the cribriform plate (the internal skull protrusion just above the nasal passages). Alteration or absence of taste/smell may also result from impairment of the brain's ability to perceive and interpret odors. Awareness and education are vital for the person to return to safe, independent living.

Hearing changes should be evaluated for possible sensori-neural hearing loss or more serious loss related to fractures of the small ear bones that conduct sound. Tinnitus (ringing, buzzing, or roaring sounds in the ear) is caused by an electrophysiological disturbance in the cochlea.

Fatigue can result from a variety of factors. Pain, sleep disturbances, depression, and the sedative effect of some medications can cause fatigue. Even fluctuations in blood sugar, blood pressure, and/or metabolic changes may contribute to feeling tired. Other post-injury factors involve the extra effort and time required to pay attention and concentrate, or to organize and complete daily tasks. The act of thinking or recalling information after MTBI may take significantly more conscious concentration. Many individuals attempt to keep up with their prior, daily routines yet their energy levels are no longer adequate. Frustration and over-stimulation by exposure to busy environments can also be fatiguing to those with MTBI.

Sensitivity to light (photophobia), touch, noise (sonophobia), crowds, movement, and heights are frequent residuals of MTBI. Sonophobia and sensitivity to movement and heights are usually consequences of disturbances in the vestibulocochlear and visual systems.

Cognition and Language

Decreased attention/concentration result from disturbances in the speed of neural processing. Cognitive deficits include attention/concentration, perception, memory, speech/language, or executive functions. The person with frontal-lobe damage will have difficulties with decision-making, planning, and initiating and completing tasks. Conversation may be rambling or tangential.

Reading and auditory comprehension problems may cause the person to decrease or avoid reading and/or listening to conversations. Oculomotor or vision disturbances, including an impaired ability to visually scan reading material or follow a moving object, should be ruled out as causes.

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