Fig. 1
CCEMRC database entry fields for patient-identifying data
Clinical Data
Pull-down menus will reveal a preselected list of primary and secondary neurological diagnoses and primary indications for EEG (Fig. 2). The selections will automatically generate billing codes. Additional clinical information is entered manually when necessary and is usually obtained from the electronic medical record and preferably from a neurology/neurocritical care consultation note.
Fig. 2
CCEMRC database entry fields for patient clinical information
Technical Information
In this section, the interpreter enters more technical information including the number of channels (usually predefined at 21), the electrode types (predefined as disk, and nearly always plastic, making them CT and MRI compatible), as well as which adhesive types are used (for allergy purposes). Note is made of video recording capability, as well as whether digital analysis tools are used. In the latter case, one specifies which quantitative methods in particular are incorporated into the analysis algorithm such as alpha/delta ratio, rhythmicity, or compressed spectral array.
EEG Results and Day/Epoch Reporting
Each day’s recording is characterized by one or more epochs; a change in epoch signifies shifts in baseline EEG due to underlying nonphysiologic changes such as burst suppression or new disease states. Within each epoch, the following must be documented.
Treatments and Medications
Daily antiepileptic medications are entered and daily dose changes are tracked. Note is made of sedative medications such as propofol, fentanyl, or midazolam, as well as any muscle-paralyzing agents. The patient’s mental status is also documented (awake, comatose, lethargic, obtunded), as well as whether the patient is intubated and whether focal neurological deficits are observed (Fig. 3).
Fig. 3
CCEMRC database entry fields for medications and clinical state of the patient
Background Activity
The predominant background rhythm is documented, including the presence or absence of a posterior dominant rhythm. This is further qualified by commenting on symmetry, voltage, variability, reactivity to stimulation, and organization. Any focal slowing or attenuation is recorded by selecting elements from a predefined list of terms and specifying their location. If additional information is required, a free text box can be filled to highlight important details (Fig. 4).
Fig. 4
CCEMRC database entry fields for background activity
Seizures, Interictal Activity, and Rhythmic/Periodic Patterns
If seizures are observed during the recording, the list item menu provides details on seizure length, frequency, location, morphology, as well as whether any associated clinical manifestations are observed. Documenting status epilepticus is an important feature of this section of the report. This section also includes a subsection stating whether or not nonepileptic events were captured (psychogenic or various motor manifestations in the critical care setting such as tremors, jerks, posturing, or rigors). Finally, mention is made of the presence of brief potentially ictal rhythmic discharges (B[i]RDs), sporadic epileptiform discharges or rhythmic and periodic patterns, and whether these are stimulation induced or not (Stimulus induced rhythmic, periodic, or ictal discharges [SIRPIDs]). The description of their frequency, amplitude, location, morphology, phases, sharpness, evolution, polarity, as well as major terms and minor modifiers is meticulously documented according to the ACNS terminology (see above) (Fig. 5).
Fig. 5
CCEMRC database entry fields for seizures, epileptiform abnormalities, and periodic patterns
Sleep, EKG, and Activation Procedures
Sleep stages are documented, and note is made of the presence or absence of sleep spindles, K complexes, or vertex sharp waves as well as any asymmetry or abnormality in the sleep architecture. This section provides an opportunity to document the EKG findings (normal sinus rhythm or arrhythmia) as well as whether activation procedures such as hyperventilation and photic stimulation are performed and what the relevant findings are. A brief description of any identified breach rhythm is also made under this section (Fig. 6).
Fig. 6
CCEMRC database entry fields for sleep, EKG, and activation procedures
Digital Analysis
In this section, the interpreter identifies to which extent his/her interpretation was aided by quantitative analysis specifically whether seizures were detected by the software (particularly useful in patients with frequent seizures). Note is also made of quantitative analysis tools that helped identify background asymmetry, if this is present (Fig. 7).
Fig. 7
CCEMRC database entry fields for digital EEG analysis
Impression
On a daily basis, an impression is formulated based on the totality of the data and usually serves as a summary of the major electrographic abnormalities documented during the entire recording. The interpreter provides an opinion as to whether the study is normal or abnormal as well as a gradation of severity in the latter case. A clinical correlation consisting of the interpretation of the results in the context of the patient’s clinical status, with an explanation as to whether or not the EEG recording fits with the clinical picture, can be provided separately from the electrographic impression. This section of the report documents whether the identified findings suggest status epilepticus or cortical irritability, cerebral dysfunction, or both. A brief differential diagnosis can be provided if the EEG is more specific of a certain condition such as focal polymorphic delta activity suggesting the possibility of a structural lesion in the brain. Any significant changes over the course of the day’s recording, including improvements or deteriorations, should be noted, for example, if observed periodic discharges become less frequent or disappear during the course of the recording. A final impression and clinical correlation should be stated at the end of the total recording session (Fig. 8).
