Neurophysiological and neuropsychological studies on post-whiplash and minor head <A NAME="top2"></A>injury patients

NEUROPHYSIOLOGICAL AND NEUROPSYCHOLOGICAL STUDIES ON POST-WHIPLASH AND MINOR HEAD INJURY PATIENTS (ABSTRACT)^*. DISSERTATION. RIBEIRÃO PRETO, 1998.

PAULA CARVALHO VIANA ^**

A small subset of chronic post-whiplash and minor head injury patients present cognitive, affective and somatic complaints which interfere with their work and daily life. The aim of the present study was to determine if those complaints correspond to EEG/FA abnormalities, delayed P300 latency and/or cognitive disorders.

The study sample which contained 81 subjects was selected from patients and volunteers of Slotervaartziekenhuis, in Amsterdam. The post-traumatic patient group contained 40 subjects with whiplash trauma and 12 who suffered minor head injury. The control groups consisted of 10 who had tension- type headaches (control group I) and 19 who were asymptomatic subjects (control group II). All subjects were submitted to analogic and digital 21 channels EEG recordings, according to the International 10-20 System. Frequency analysis (FA) was performed on 36-42 second epochs of artifact-free EEG under conditions of Eyes Open (EO) and Eyes Closed (EC). P300 was performed on 25 post-whiplash/minor head injury patients and 16 asymptomatic controls. Post-whiplash/minor head injury patients were submitted to complete neurological examination, conventional memory and concentration tests and to a recently developed malingering test.

Neurological examination showed abnormalities in 37 of 52 patients, which consisted mostly of musculoskeletal signs. Analogic EEG did not demonstrate significant differences among post-whiplash, minor head injury patients and headache subjects, with sharp waves in the temporal area being the most common abnormality. All 33 of the post-whiplash/minor head injury patients who had been submitted to FA presented diminished beta 2 and gamma activity in the occipital area when compared to control group II, whereas tension-type headache subjects had less beta 1 reactivity in parietal area, when compared to the same group (p<=0.01). No significant differences in FA were observed when post-whiplash/minor head injury patients were compared to tension-type headache subjects. There were no statistical differences in P300 data between patients and control group II, concerning latency, amplitude or topography (p<= 0.05). A strong negative correlation between memory tests and P300 latency was observed after excluding 4 under-performing patients of the 17 submitted to the malingering test. The results of neuropsychological examination were abnormal in 5 of 13 non-malingering patients (38.4%), primarily in the memory tests.

These data demonstrate that whiplash and minor head injury are related to discrete abnormalities on neurological examination. Sharp waves can be found in the EEG recordings, however post-traumatic epilepsy was not observed. Punctual differences in beta activity may have been related to cognitive/emotional disabilities in post-traumatic patients. Whiplash trauma and minor head injury did not change alpha topography, mean alpha peak frequency and P300 latency, amplitude or topography. FA has been shown to be sensitive for the detection of minor abnormalities, not specific for post-whiplash/minor head injury patients, but that may be related to the neuropsychological under-performance of these patients. Further studies which exclude malingering patients should provide more reliable correlations among FA data, P300 data and the results of neuropsychological examination.

KEY WORDS: head injury, whiplash injury, EEG, brain mapping, headache.

** Address: Rua Maracaju 1491 / 16, 14051-120 Ribeirão Preto SP, Brasil.

*

Estudos neurofisiológicos e neuropsicológicos em pacientes com trauma cervical do tipo chicote e trauma cerebral mínimo. Dissertação de Mestrado, Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (Área: Neurologia). Orientador: Américo Ceiki Sakamoto.

Publication Dates

• Publication in this collection
  06 Dec 2000
• Date of issue
  Sept 1999