An implantable neurological stimulation lead assembly (10) having multiple elongated stimulation leads coupled together in parallel with a lead coupler (13) for delivering electrical impulses to subcutaneous tissue for treatment. The lead coupler (13) includes a set of interconnected expandable elastic collars (15), one collar for each lead (11,12), whereby the collars (15) respectively receive and retain the leads (11,12) with an elastic constraint in a predetermined side by side array. The set of interconnected lead coupler collars (15) are interconnected with a releasable connection (23) whereby the lead assembly (10) may be configured as a single or multiple lead assembly.