Abnormal movements and diaphragmatic flutter in a case of suspected induced illness

Background

Drug ingestion is an important differential to consider early in the presentation of abnormal movements and altered levels of consciousness in children. It is a differential which often does not present with a clear history, particularly in cases of non-accidental administration, and there is often a delay while awaiting results of extensive testing such as cerebrospinal fluid (CSF) results, PCRs and MRIs before a urine drug screen is considered and then a further delay while awaiting the results of urine drug analysis. These are important cases not to be missed, particularly in the case of non-accidental ingestion.

We report a case with an unusual constellation of symptoms given the two different classes of medications which were administered. A history of drug ingestion was not initially provided. Given repeat positive urine drug screens over 5 days, it was highly suspicious that the medication was continued to be inappropriately administered in hospital, highlighting the importance of strict control of formula preparation for infants in hospital.

Case presentation

A 6-month-old girl child initially presented to her general practitioner with an abnormal breathing pattern and a history of several days of coryzal symptoms. An ambulance was called for her altered level of consciousness and she was found to have a Glasgow Coma Scale of 3 when the ambulance arrived. She was urgently transferred to her closest peripheral hospital.

The infant was previously well with no significant medical history. There was no history of fevers, trauma or drug ingestion. She was immunised, took no regular medication and was achieving appropriate developmental milestones. She had no significant family history of seizures or other medical illness.

She was initially treated with intranasal midazolam by paramedics for potential seizures, then on arrival to the emergency department was empirically covered with ceftriaxone and aciclovir for possible meningitis. She had a CT brain performed which was normal and was observed on the ward for 48 hours.

The patient continued to have an abnormal pattern of breathing throughout her peripheral hospital admission, so her progress was discussed with subspecialty teams at the closest tertiary children’s hospital with a plan for an elective transfer to conduct further investigation. She then however progressed to having longer episodes of profound unresponsiveness warranting rapid response teams, resulting in an urgent retrieval to the paediatric intensive care unit at the tertiary children’s hospital.

Also complicating her diagnostically difficult case, she developed writhing, purposeless movements and increasing agitation with associated tachycardia and hypertension followed by intermittent bradycardia and periods of drowsiness. Doses of midazolam were trialled for abnormal movements with some improvement, but there were no changes in the breathing pattern.

While in the paediatric intensive care unit, her symptoms eventually settled, and she was discharged to the ward. Unfortunately, she developed a worsening of her movements, tachycardia and insomnia within 24 hours on the ward resulting in a re-admission to the paediatric intensive care unit. It was noted at this time she was flushed, agitated and had dilated reactive pupils.

The patient’s admission was also complicated by the loss of multiple peripheral cannulas and an extravasation injury from intravenous aciclovir.

Investigations

Throughout her admission, the major investigations performed included a lumbar puncture, with both bacterial cultures and viral PCRs which were all negative, a normal electroencephalogram (EEG) to investigate seizures and an MRI brain, spine and chest (to investigate potential phrenic nerve lesions causing diaphragmatic flutter) which was also negative. There were some normal baseline bloods including cell counts, electrolytes, thyroid function tests, blood glucose levels and liver function tests, and normal urine metabolic screens. An abdominal X-ray was performed (due to some abdominal distension) which showed non-specific extensive increased bowel gas.

As her diagnosis remained unclear, a urine drug screen was eventually performed and results became available on her second admission to the paediatric intensive care unit, which were positive for amfetamines. A more detailed analysis sent to another tertiary laboratory confirmed lisdexamfetamine and clonidine use. On further testing of multiple urines already provided to the pathology laboratory, lisdexamfetamine was present on initial presentation and then again 5 days later when she was re-admitted to the paediatric intensive care unit, suggesting a repeat ingestion on the ward. Clonidine was present in all four urine samples across 5 days. During the child’s admission, it was noted that her mother was preparing her feeds from a tin of open formula by her bedside.

Differential diagnosis

The patient was empirically covered for sepsis and meningitis given how profoundly unwell she was at presentation. Her CSF analysis and cultures were however negative, and her antibiotics were able to be ceased.

Seizures were also considered due to her decreased conscious levels and abnormal movements. Her movements did however appear to be more choreoathetoid in nature as opposed to rhythmic typical seizure-like movements. These episodes were not necessarily followed by postictal periods and there was no response to midazolam. She also had a normal EEG.

Another main differential was an intracerebral mass considering her altered levels of consciousness, abnormal movements and intermittent hypertension with associated bradycardia concerning for Cushing reflex. The possibility of a spinal cord or phrenic nerve lesion was also considered with her diaphragmatic flutter; however, a normal MRI brain, chest and spine excluded these differentials.

The final diagnosis of drug ingestion was considered after these main differentials were excluded.

Outcome and follow-up

The patient’s symptoms completely resolved. There was involvement with the child protection team, and she was eventually discharged into the care of a family friend with supervised visits allowed with her mother. Social work were also involved in her ongoing care.