Nightmares that mislead to diagnosis of reactivation of PTSD

Abstract

Background: Sleep disturbance is a common characteristic of patients with post-traumatic stress disorder (PTSD). Besides the clinical descriptions of nightmares and insomnia, periodic limb movements (PLMs) are reported to co-occur in PTSD. Although the causal relationship between sleep disturbance and PTSD is not fully understood, sleep disturbance is an independent risk factor for the development and reactivation of PTSD. In contrast, the link between PTSD and REM sleep behaviour disorder (RBD) is less clear.

Method: A case report is presented to illustrate differential diagnosis and time course of sleep disturbance in the context of PTSD.

Result: A 63-year-old man who had been successfully treated for PTSD but who suffered the re-occurrence of disturbed sleep due to RBD and PLM, which was misdiagnosed as reactivation of PTSD.

Conclusions: RBD can mimic PTSD-related nightmares. Accurate diagnosis of sleep disturbance in PTSD is relevant for treatment and prognostic evaluation.

Keywords: REM sleep behaviour disorder; nightmares; periodic limb movements; posttraumatic stress disorder; sleep disturbance.

Fig. 1

Example (10 seconds) of faulty regulation of motor activity in REM sleep indicating RBD. Note: The time line of Fig. 1 is 10 s. Legend top to bottom: EOG vert./hor.=electrooculogram—eye movements vertical or horizontal; F4, F3=frontal electrodes right and left; C4, C3=central electrodes right and left; O2, O1=occipital electrodes right and left; EMG electromyogram=muscle activity; ment. subment.=mental, submental; EMG tib li, tib re.=left and right muscle activity of lower leg (mm. tibiali); Atmg.=breathing; nas.=nasal; thorak.=thoracic; Schnarchmikro=snoring; EKG=ECG; SAO2=O2-saturation. Note the beginning of muscle activity in the form of twitches, moving to almost continuous muscle activity, first in the right m. tibialis anterior, then spreading to the left one, too. On the EOG, rapid eye movements are clearly visible, indicating ongoing REM. In the last third of the episode some muscle activity spreads to head muscles as well. No muscle activity in mental and submental muscles during the whole event; that is, these muscles maintained REM-atonia.

Fig. 2

PSG results before initiating clonazepame and pramipexole treatment. Note: from top to bottom: 1, hypnogram showing the NREM-REM-cycles and interruptions thereof; 2, display of arousals; 3, overall leg movements; 4, periodic leg movements. Notice heavy fragmentation of REM sleep periods, often correlated to periodic limb movements. In NREM there is a long cluster of PLMs.